Mcat Physical Scince Review

Front 1

Oxidation

Back 1

A rxn in which a species loses electrons

Front 2

Oxidizing agent

Back 2

A species that is reduced in the process of oxidizing anouther species

Front 3

Redox half-reaction

Back 3

hypothetical equation showing only the species that is oxidized or reduced in a redox rxn and the correct number of electrons transferred between the species in the complete balanced equation.

Front 4

Reducing agent

Back 4

A species that is oxidized in the process of reducing anouther

Front 5

Reduction

Back 5

A rxn in which a species gains electrons

Front 6

Reduction potential

Back 6

A measure of the tendency of a species to be reduced, commonly used in identifying the anode and cathode of an electrochemical cell.

Front 7

Standard electromotive force

Back 7

the difference between the two reduction potentials of half-cells in a cell under standard conditions
25C, 1M and 1atm

E cell = E cathode - E anode

Front 8

Standard reduction potential

Back 8

The tendency of a species to be reduced, as measured at 25C when reacting species are of 1M concentration or 1atm (for gases)

Front 9

Acceleration

Back 9

A vector quantity describing a change in velocity over the elapsed time.

a= Δv/Δt

Front 10

Displacement

Back 10

A vector quantity describing the straight-line distance between an initial and final position of some particle or object.

Front 11

Scalar

Back 11

A quantity that only has magnitude but no direction

Front 12

Speed

Back 12

A scalar quantity describing distance traveled over the time required to travel that distance

d/t

Front 13

Vector

Back 13

A quantity that has both magnitude and direction

Front 14

Velocity

Back 14

A vector quantity describing and object's displacement over the elapsed time

v = Δx/ Δt

Front 15

Centripetal acceleration

Back 15

The acceleration of an object traveling in a circle with a constant speed, equal in magnitude to the velocity squared divided by the radius of the circle traversed. The direction of the acceleration always points toward the center of the circle

Front 16

Force

Back 16

A vector quantity describing the push or pull on an object. The SI unit for force is the Newton (N)

Front 17

Friction Force

Back 17

An antagonistic force that points parallel and opposite in direction to the movement (or attempted movement) of an object

Front 18

Gravity

Back 18

A ubiquitous attractive force existing between any two objects, whose magnitude is directly proportional to the product of the two masses observed and inversly proportional to the square of their distance

Front 19

Mass

Back 19

A scalar quantity used as a measure of an object's inertia

Front 20

Newton's First Law

Back 20

If a body has either a zero or constant speed, it will remain that way unless a net force acts upon it.

Front 21

Newton's second law

Back 21

When a net force acts on a body it will have a net acceleration pointing in the direction of the net force that is proportional to the body's mass in the following relationship:
F = ma

Front 22

Newton's third law

Back 22

If body A exerts a force Fa on body B, then body B exerts a force that is equal in magnitude but opposite in direction to Fa, "law of action and reaction"

Front 23

Normal force

Back 23

Perpendicular component of the force caused when two surfaces push against each other Fn

Front 24

Rotational equilibrium

Back 24

State where the sum of the torques acting on a body is zero, giving it no net angular acceleration.

Front 25

Torque

Back 25

The magnitude of a force acting on a body times the perpendicular distance between the acting force and the axis of rotation

Front 26

Translational equilibrium

Back 26

State where the sum of the forces acting on an object is zero, giving it no net acceleration

Front 27

Weight

Back 27

A force that measures the gravitationalpull on an object, given by the object's mass times its gravitational acceleration; mg, where g is 9.8 m/s2 as measured on Earth

Front 28

Center of gravity

Back 28

The point on some object or body at which the entire force of gravity is considered to act on.

Front 29

Center of Mass

Back 29

The point on some object or body at which all of its mass is considered to be concentrated

Front 30

Completely elastic collisions

Back 30

type of collision in which both momentum and kinetic energy are conserved. That is, the sum of the initial kinetic energies right before the collision = the sum of the final kinetic energies after the collision

Front 31

Conservation of mechanical energy

Back 31

when only conservative forces act on an object and work is done, energy is conserved and described by the equation:
ΔE = ΔKE + ΔPE = 0

Front 32

Conservation of Momentum

Back 32

The momentum of a system remains constant when there are no net external forces acting on it

Front 33

Conservative force

Back 33

A force, such as gravity, which performs work over a distance that is independent of the path

Front 34

Impulse

Back 34

Often denoted by j, it is the change in momentum, given by ∆p.

Front 35

Kinetic energy

Back 35

The energy of an object in motion, calculated by the equation: KE = 1/2mv2 and given in the SI units of Joules (J)

Front 36

Momentum

Back 36

Often denoted by p, it is a vector quantity given by an object's mass times its velocity

Front 37

Nonconservative force

Back 37

A Force, such as friction, which performs work over a distance that is dependent on the path taken between the initial and final positions

Front 38

Potential energy

Back 38

The energy of an object due to its height off the ground level, calculated by the equation PE=mgh

Front 39

Power

Back 39

The rate at which work is done, given by the equation Power = W/∆t, where W is work and t is time(in seconds)

Front 40

Work

Back 40

The quantity measured when a constant force acts on a body to move it a distance d, calculated by the equation Work = Fd cosѲ

Front 41

Work energy theorem

Back 41

A theorem stating that the net work performed on an object is related to the change in kinetic energy of that body, given by the equation W=∆KE

Front 42

Calorie

Back 42

A unit of heat (C) that equals 10000 calories(c) or 4,184 Joules

Front 43

Conduction

Back 43

Form of heat transfer where heat energy is directly transferred between molecules through molecular collisions or direct contact.

Front 44

Convection

Back 44

Form of heat transfer applying to fluids (liquids and gases) where heated material transfers energy by bulk flow and physical motion

Front 45

First law of thermodynamics

Back 45

The change in internal energy of a system (∆U) is equal to the heat (Q) transferred into the system minus the energy lost by the system when it performs work (W). ∆U = Q-W

Front 46

Heat of fusion

Back 46

The heat of transformation corresponding to a phase change from either solid→liquid or
from liquid→solid

Front 47

Conservation of Momentum

Back 47

The momentum of a system remains constant when there are no net external forces acting on it

Front 48

Conservative force

Back 48

A force, such as gravity, which performs work over a distance that is independent of the path

Front 49

Impulse

Back 49

Often denoted by j, it is the change in momentum, given by ∆p.

Front 50

Kinetic energy

Back 50

The energy of an object in motion, calculated by the equation: KE = 1/2mv2 and given in the SI units of Joules (J)

Front 51

Momentum

Back 51

Often denoted by p, it is a vector quantity given by an object's mass times its velocity

Front 52

Nonconservative force

Back 52

A Force, such as friction, which performs work over a distance that is dependent on the path taken between the initial and final positions

Front 53

Potential energy

Back 53

The energy of an object due to its height off the ground level, calculated by the equation PE=mgh

Front 54

Power

Back 54

The rate at which work is done, given by the equation Power = W/∆t, where W is work and t is time(in seconds)

Front 55

Work

Back 55

The quantity measured when a constant force acts on a body to move it a distance d, calculated by the equation Work = Fd cosѲ

Front 56

Work energy theorem

Back 56

A theorem stating that the net work performed on an object is related to the change in kinetic energy of that body, given by the equation W=∆KE

Front 57

Calorie

Back 57

A unit of heat (C) that equals 10000 calories(c) or 4,184 Joules

Front 58

Conduction

Back 58

Form of heat transfer where heat energy is directly transferred between molecules through molecular collisions or direct contact.

Front 59

Convection

Back 59

Form of heat transfer applying to fluids (liquids and gases) where heated material transfers energy by bulk flow and physical motion

Front 60

First law of thermodynamics

Back 60

The change in internal energy of a system (∆U) is equal to the heat (Q) transferred into the system minus the energy lost by the system when it performs work (W). ∆U = Q-W

Front 61

Heat of fusion

Back 61

The heat of transformation corresponding to a phase change from either solid→liquid or
from liquid→solid

Front 62

Heat of transformation

Back 62

The amount of heat required to change the phase of a substance, calculated by the equation q=mL, where q is heat, m is the mass of the substance and L is the heat of transformation for that substance

Front 63

Heat of vaporization

Back 63

The heat of transformation corresponding to a phase change from liquid→gas or
gas→liquid

Front 64

Kelvin

Back 64

The most commonly used tempreture scale (SI units) that ranges up from absolute zero.

T Kelvin = T Celcius + 273

Front 65

Pressure

Back 65

The force per unit area: F/A

Front 66

Radiation

Back 66

Form of heat transfer accomplished by electromatic waves, which can travel through a vacuum

Front 67

Second law of thermodynamics

Back 67

When a thermodynamic process moves a system from one state of equalibrium to anouther, the entropy (S) of that system combined with that of its surroundings will either increase or remain unchanged; for irreversible processes entropy will increase and for reversible processes entropy will not change

Front 68

Tempreture

Back 68

A measure of the heat content that a body possesses measured on either the Kelvin, Celsius or Fahrenheit scale

Front 69

Thermal expansion

Back 69

The expansion of a solid as a result of increasing tempretures, calculated by the equation ∆L = αL∆T, where L in the length, α is the coefficient of the linear expansion and T is the tempreture

Front 70

Thermodynamics

Back 70

The study of heat transfer and its effects

Front 71

Volume expansion

Back 71

The expansion in volume of a liquid as a result of increasing tempretures, calculated by the equation ∆V = βV∆T
Where V is volume and β is the coefficient of volume

Front 72

Absolute pressure

Back 72

The pressure below the surface of a liquid that depends on the gravity and surface pressure

Front 73

Adheasion

Back 73

A type of attractive force that molecules of a liquid feel towards molecules of anouther substance, such as in the adheasion of water droplets to a glass surface

Front 74

Archimede's principle

Back 74

A body that is fully or partially immersed in a liquid will be buoyed up by a force that is = to the weight of the liquid displaced by the body

The fluid displaced has a weight W = mg. The mass can now be expressed in terms of the density and its volume, m = pV. Hence, W = pVg.

Front 75

Bernoulli's equation

Back 75

The simplified form of Bernoulli's equation can be summarised in the following memorable word equation:

static pressure + dynamic pressure = total pressure
p + q = Po

Front 76

Bulk Modulus

Back 76

A term that describes a fluid's resistance to compression under a pressure, denoted by B and measured by the ratio of stress (pressure change) to stain; ∆P/(∆V/V)

Front 77

Cohesion

Back 77

A type of attractive force by liquid molecules toward each other. Cohesion is responsible for surface tension.

Front 78

Continuity equation

Back 78

The equation following the law that the mass flow rate of fluid must remain constant from one cross-section of a tube to anouther, given by
A1xV1 = A2xV2

Front 79

Density

Back 79

A scalar quantity defined as the mass per unit volume, often denoted by p.

Front 80

Gauge Pressure

Back 80

The pressure above the atmospheric pressure, given only by pgz;

Front 81

Laminar flow

Back 81

The simplist type of liquid flow through a tube where thin layers of liquid slide over one another, occuring as long as the flow rate remains below a critical velocity Vc

Front 82

Pascal's principle

Back 82

principle stating that when a pressure is applied to one point of an enclosed fluid, that pressure is transmitted in equal magnitude to all points within that fluid and to the walls of its container. This principle forms the basis of the hydrolic lift.

Front 83

Shear modulus

Back 83

A term describing a sollid's resistance to shear stree, denoted by S and measured by the ratioof shear stress (F/A) to stain (x/h). Results when a force is applied parallel to the surface area.

Front 84

Specific gravity

Back 84

A dimensionless quantity given by the density of a substance divided by the density of water:

P water = 1g/ml or 1g/cm3

Front 85

Streamline

Back 85

Lines that trace out the path of water particles as they flow in a tube with out ever crossing each other.

Front 86

Turbulent flow

Back 86

Type of liquid flow that occurs when the flow rate in a tube exceeds Vc. The motion of the fluids that is not adjacent to the container walls is highly irregular, forming vorticles and high flow resistance

Front 87

Viscosity

Back 87

The measure of internal friction in a fluid

Front 88

Young's modulus

Back 88

A term used in characterizing the elasticity of a solid, denoted by Y and measured by the ratio of the stress (F/A) to strain (∆L/L). Results when a force is applied perpendicular to the surface area.

Front 89

Coulomb

Back 89

The SI unit of electric charge, denoted by C.

Front 90

Coulomb's law

Back 90

The law describing the electrostatic force that exists between two charges, q1 and q2:

F coulomb = kq1q2/r2

Front 91

Dipole moment

Back 91

A vector quantity resulting from a electric dipole, equal to the product of the charge magnitude q and the distance separating the two charges d.

Front 92

Electric dipole

Back 92

The result of having two charges of opposite sign and equal magnitude separated by a short distance, d.

Front 93

Electric field

Back 93

The electrostatic force that a source charge qs would exert on a positive test charge q0 within its proximity divided by that test charge; E=Fcoulomb/ q0

Front 94

Electric field lines

Back 94

Imaginary lines that show the direction in which a positive test charge is accellerated by the coulomic force due to the electric field of a source charge

Front 95

Electric potential

Back 95

The amount of electric potential energy per unit charge; the work required to bring a positive test charge q0 from infinity to within an electric field of anouther positive source charge Q divided by that test charge

V = kQ/r

Front 96

ELectrical potential energy

Back 96

The amount of work required to bring a test charge q0 from infinity to a point within the electric field of some source charge Q.

EPE = q0V

Front 97

ELectrostics

Back 97

The study of electrical charges at rest or in motion and the forces between them

Front 98

Equipotential lines

Back 98

Concentric circles emanating from a source charge that cross its electric field lines perpendicularly. No work is required for a test charge to travel along the circumference of an equipotential line since the potential at every point along that line is the same

Front 99

Fundamental unit of charge

Back 99

The smallest measured electric charge, belonging to an electron; -1.6 x10-19 C.

Front 100

Potential difference

Back 100

The difference in electric potential between two points in an electric field, also termed voltage

(ΔV)

Front 101

Current

Back 101

The flow of charge as it moves across a potential difference (voltage), denoted I and measured by the amount of charge passing through a conductor over a unit of time

Δq/Δt

Front 102

Diamagnetic material

Back 102

A material whose atoms have NO net magnetic field and is therefore repelled from the pole of a magnet

Front 103

Ferromagnetic

Back 103

A material whose atoms have a net magnetic field and, below a critical tempreture are strongly attracted to a magnet pole

Front 104

Loop-wire magnetic field

Back 104

The magnetic field produced at the center of a circular loop of current-carrying wire with a radius of r

B= μ0i/ 2r

Front 105

Magnetic field

Back 105

Field vectors created by moving charges and permanent magnets that in turn exert a magnetic force on moving charges and current carrying wires

Front 106

Magnetic force

Back 106

A force exert on a charged particle moving through a magnetic field, calculated by:
F = qvB sinθ

where the angle denotes that only charges moving perpendicular to the magnetic field experience a force

Front 107

Magnetic force on a current carrying wire

Back 107

Equation used to measure the force exerted on a current carrying wire due to magnetic field:

F = ILB sinθ

where I is the current, L is the length of the wire, B is the magnitude of the magnetic fiels and θ is the angle at which the wire and wire intersect the B-field vectors

Front 108

Paramagnetic material

Back 108

A material whose atoms have a net magnetic field and under conditions that allow the alignment of the individual magnetic fields, exhibits an attraction toward the pole of a magnet

Front 109

Permeability of free space, μ0

Back 109

Term denoted by μ0 and = to 4π x 10-7 Telsa meter/Ampere; used in the equation measuring the magnetic field produced by a current-carrying wire, B = μ0 I/2πr

Front 110

Right-hand rule

Back 110

A common method used to determine the direction of the magnetic force vector. The thumb points in the direction of the charge's velocity, the fingers point in the direction on the magnetic (B) field, and the palm points in the direction of the acting force

Front 111

Straight wire magnetic field

Back 111

The magnetic field produced at a perpendicular distance r from a straight current carrying wire, calculated by:

B = μ0 I/2πr

Front 112

Alternating current

Back 112

Current that flows through a conductor in two directions that are periodically altered

Front 113

Capacitance

Back 113

A measure (SI units of Farads) of a capacitor's ability to store charge, calculated by the ratio of the magnitude of charge on one plate to the voltage across the two plates

Front 114

Capacitor

Back 114

An electric device used incircuits that is basically composed of two conducting plates separated by a short distance and works to store electric charge

Front 115

Conductor

Back 115

A material in which electrons can move with relative ease

Front 116

Dielectric

Back 116

An insulating material placed between the two plates of a capacitor. If the circuit is plugged into a current source, more charge will be stored in the capacitor. If the circuit is not plugged into a current source, the voltage of the capacitor will decrease

Front 117

Dielectric constant

Back 117

A dimensionless number that indicated the factor by which capacitance is increased when a dielectric is placed in between the plates of a capacitor:

C' = KC

C' is the new capacitance

Front 118

Direct current

Back 118

Current that flows through a conductor in one direction only

Front 119

Electric circuit

Back 119

A conducting pathway that contains one or more voltage sources that drive an electric current along that pathway and through connected passive circuit elements (such as resistors)

Front 120

Electromotive force

Back 120

The energy gained by an electron when it is accelerated through a potential difference of 1 volt, given by qV

where q is 1.6 x 10-19 and V is 1 volt

Front 121

Electron volt

Back 121

The voltage created by a potential difference between the two terminals of a cell when no current is flowing

Front 122

Insulator

Back 122

A material in which electrons cannot move freely

Front 123

Kirchhoff's laws

Back 123

A. In accordance with the conservation of electric charge, the sum of currents directed into a node or junction point in a circuit = the sum of the currents directed away from that point.

B. The sum of the voltage sources in a circuit loop is = to the sum of voltage drops along that loop

Front 124

OHM's Law

Back 124

Law stating that the voltage drop across a resistor is proportional to the current flowing through it, given V=IR

Front 125

Power dissipated by resistor

Back 125

Thr rate at which the energy flowing charges through a resistor is dissipated, given by the equation P = IV

Front 126

Resistance

Back 126

The natural tendency of a conductor to block current flow to a certain extent resulting in loss of energy or potential. Resistance is = to the ratio of the voltage applied to the resulting current

Front 127

Resistivity

Back 127

Intrinsic property of a conductor denoted by p used to measure its resistance in the equation R = pL/A

where L is the length of the conductor and A is its cross-sectional area

Front 128

Amplitude

Back 128

The point of maximum displacement from the equalibrium position

Front 129

Anti-node

Back 129

The point of maximum displacement in a standing wave

Front 130

Beats

Back 130

A periodic frequency resulting from the superposition of two waves that have slightly different frequencies

f beat = |f1 - f2|

Front 131

Constructive interference

Back 131

When two overlapping waves are in phase their amplitudes add together

Front 132

Destructive interference

Back 132

When two overlapping waves are out of phase they subtract and can cancel each other if they have the same amplitude and are 180 degrees out of phase

Front 133

Doppler Effect

Back 133

When a source emitting a sound and a detector recieving the sound move relative to each other, the virtual frequency fv' detected is less than or greater than the actual frequency emitted f, depending on whether the source and detector move toward or away from each other.

f' = f(V + or- Vd) / (V+or- Vs)

Front 134

Frequency

Back 134

Number of cycles per second measured in SI units of Hz, where 1 Hz = 1 cycle/second

Front 135

Fundamental frequency

Back 135

The lowest frequency that a standing wave can support, given by the equation f=nv/2L for strings fixed at both ends and pipes open at both ends and f = nv/4L for pipes closed at one end, where n=1; First Harmonic

Front 136

Harmonic Series

Back 136

All the possible frequencies that a standing wave can support

Front 137

Hook's Law

Back 137

The equation describing the restoring force of a mass-spring system, given by
F=-kx, where x is the displacement from the equalibrium position

Front 138

Intensity

Back 138

The power transmitted per unit area, given by the equation P= IA, where I is intensity, A is area and P is power

Front 139

Longitudinal Wave

Back 139

Type of wave, such as sound, whose oscillation is along the direction of its motion

Front 140

Node

Back 140

The point of zero displacement in a standing wave

Front 141

Period

Back 141

Number of seconds it takes to complete one cycle, denoted T; the inverse value of Frequency

Front 142

Phase difference

Back 142

The angle by which the sine curve of one wave leads or lags the sine curve of anouther wave

Front 143

Resonance (physics)

Back 143

If a standing wave undergoes a forced oscillation due to an external periodic force that has a frequency = to the natural frequency of the oscillating system, the amplitude will reach a maximum

Front 144

Simple harmonic motion

Back 144

The motion of an object oscillating back and forth about some equalibrium point when it is subject to an elastic linear restoring force

Front 145

Sound level

Back 145

A quantity measured in decibels (dB) and denoted by B, given by the equation:

B = 10 log I/I0
where I0 is a reference intensity of 10-12 W/m2

Front 146

Spring constant

Back 146

A measure of a spring's stiffness, denoted by k.

Front 147

Transverse wave

Back 147

Type of wave, such as light whose oscillation is perpendicular to its direction of motion

Front 148

Wavelength

Back 148

A quantity equal to the distance between any two equivelent consecutive points along a wave, such as two consecutive crest peaks

Front 149

Wave speed

Back 149

The speed of a wave, which is related to the frequency and wavlength
v= frequency x wavelength

Front 150

Converging lens

Back 150

A lens with a thick center that converges light rays at a point where the image is formed

Front 151

Converging Mirror

Back 151

A concave mirror with a positive focal length

Front 152

Diffraction

Back 152

The spreading-out effect of light when it passes through a small slit opening

Front 153

Dispersion

Back 153

The phenomenon observed when white light is incident on the face of a prism and emerges on the opposite side with all its wavelengths split apart. This occurs because wavelength is related to the index of refraction by the relationship:
n=c/(frequency x wavelength)

Therefore a small wavelength has a large n and in turn a small angle of refraction

Front 154

Divering lens

Back 154

A lens with a thin center that diverges light after refraction and always forms a virtual image

Front 155

Diverging Mirror

Back 155

A convex mirror with a negative focal length. Diverging mirrors always produce virtual images

Front 156

Electromagnetic spectrum

Back 156

The full range of frequencies and wavelengths for electromagnetic waves broken down into the following regions (in descending order of wavelength): radio, infrared, visble light, untraviolet, x-ray and gamma ray

Front 157

ELectromagnetic waves

Back 157

When a magnetic field is changing it causes a change in an electric field and visa versa, resulting in the propagation of a transverse wave containing a magnetic and electric field that are perpendicular to each other

Front 158

Focal length

Back 158

The distance between the focal point and the mirror or lens. For sperical mirror the focal length is equal to one-half the radius of curvature

Front 159

Index of refraction

Back 159

Ratio of thespeed of light in a vacuum to the speed of light through amedium, given by: n=c/v; factor by which the c is reduced as light travels from a vacuum into another medium

Front 160

Interference

Back 160

When superimposed light waves are in phase, their amplitudes add (constructive interference) and the appearance is brighter. When superimposed light waves are out of phase, their amplitudes subtract (destructive interference) and the appearance is darker

Front 161

Magnification

Back 161

A dimensionless value denoted by m given by the equation:
m = -i/o

where i is the image height and o is object height. A negative m denotes an inverted image whereas a positive m denotes and upright image

Front 162

Plane Mirror

Back 162

A mirror in which incident light rays remain parallel after reflection, always producing a virtual image that appears to be the same distance behind the mirror as the object is in front of the mirror

Front 163

Plane-polarized light

Back 163

Light that has been passed through a polarizing filter, only allowing the transmission of waves containing electric field vectors parallel to the lines of the filter

Front 164

Real image

Back 164

An image produced at a point where the light rays actually converge or pass through. For mirrors this would be on the side of the object; for lenses it would be on the opposite side of the object

Front 165

Speed of light

Back 165

The speed of electromagnetic waves traveling through a vacuum, given by the equation
c = wavelength x frequency,

where c is a constant is equal to 3.00 x 108 m/s

Front 166

Spherical mirror

Back 166

A curved mirror that is essentially a small, cut-out portion of a sphere mirror, having a ceter of curvature C and radius of curvature r

Front 167

Virtual image

Back 167

Animage produced at a point where light does not actually pass or converge. For mirrors this would be on the opposite site of the object; for lenses it would be on the same side as the object.

Front 168

Fluorescence

Back 168

The phenomenon observed when an atom is excited by UV light and the electrons return to the ground state in two or more steps, emitting photons of lower frequency (often in the visible light spectrum) at each step

Front 169

Photoelectric effect

Back 169

The phenomenon observed when light of a certain frequency is incident on a sheet of mental and causes it to emit an electron

Front 170

Work function

Back 170

The minimum amount of photon energy required to emit an electron from a certain mental. This quantity, denoted by W, is used to calculate the residual kinetic energy of an electron emitted by a metal, given by:

KE = hf - W

where hf is the energy of a photon

Front 171

Alpha decay

Back 171

Nuclear reaction in which an alpha-particle is emitted

Front 172

Beta Decay

Back 172

Nuclear reaction in which a B-particle is emitted

Front 173

Binding energy

Back 173

The energy that holds the protons and neurons together in the nucleus, defined by the equation E=mc2, where m is the mass defect and c is the speed of light in a vacuum

Front 174

Electron capture

Back 174

A radioactive process in which a nucleus captures an inner-shell electon that combines with a proton to form a neutron. As a result, the atomic number decreases by 1, but the atomic mass remains the same

Front 175

Fission

Back 175

The nuclear reaction in which a large nucleus splits up into smaller nuclei.

Front 176

Fusion

Back 176

The nuclear reaction in which two or more small nuclei combine to form a larger nucleus

Front 177

Gamma Decay

Back 177

The atomic emission of high energy photons, also known as y-particles

Front 178

Half-life

Back 178

The amount of time it takes for one-half of a radioactive sample to decay given by the equation T1/2 = ln2/wavelength

Front 179

Mass Defect

Back 179

The diiference between an atom's atomic mass and the sum of its protons and neutrons

Front 180

Positron

Back 180

An anti-electron, denoted B+ or e+, emitted in a nuclear

Front 181

Atom

Back 181

The basic building block of all matter in the universe. An atom is made up of three main components; Protons, neutrons, and electrons

Front 182

Atomic absorption spectrum

Back 182

The spectrum of certain absorbed wavelengths of light corresponding to an atom's spectrum of emitted frequences of light

Front 183

Atomic emission spectra
(excited -> ground)

Back 183

The discontinuous line spectra of light produced when excited atoms return to their ground state and emit photons of a certain frequency

Front 184

Atomic mass unit
(AMU)

Back 184

The unit of mass equal to 1/12 the mass (in grams) of a carbon-12 atom; 1 amu is approximately equal to the mass of a proton

Front 185

Atomic number
(# proton)

Back 185

The number of protons in an element, often denoted by the letter "Z"

Front 186

Atomic Weight
(mass of isotope)

Back 186

The average mass, measured in amu, of all the isotopes of a given element as they occur naturally

Front 187

Aufbau Principle
(fill low->high)

Back 187

Electrons fill an atom in order of increasing energy level

Front 188

Azimuthal Quantum Number

(2nd # l)

Back 188

The second quantum number. Designated by the letter l, it means "angular momentum" and refers to the subshells within each principle quantum energy level. l can take on the value of an integer in the 0 to n - 1 range

Front 189

The Bohr model

Back 189

A model of the atom postulating that electons are located in discrete circular orbits about the nucleus. In this model, the electostatic force between the positive nucleus and negative electron acts as the centripetal force keeping the electron in orbit

Front 190

Diamagnetic

Back 190

An atom or subtance that contains no unpaired electrons and is consequntly repelled by a magnet

Front 191

Electron

Back 191

A subatomic particle that orbits the nucleus and has a charge of -1. The electron has a negligile mass and is often denoted by the symbol e-

Front 192

Electron Configuration

Back 192

The patterned order by which electrons fill subshells and energy levels in an atom. The first number designates the principle quantum number (n), the letter - s, p,d,f,g specifies the subshell (l) and the superscript indicates the number of electron in that subshell.

Front 193

Heidenberg Uncertainty Priciple
(no idea where e- is)

Back 193

The quantum mechanical idea that we cannot measure the exact momentum and position of an orbiting electron simultaneosly. That is, the more accurately we measure an electron's momentum, the less we know about its exact position

Front 194

Hund's Rule
(e- need space)

Back 194

Electrons will first fill equal-energy orbitals of a subshell unpaired and with parallel spins before being coupled with other electrons of opposite spins in the same orbital. This method of maximizing the number of half-filled orbitals allow for the most stable distribution of electrons with in a subshell

Front 195

Isoelectronic
(same e- config)

Back 195

Two different elements that share the same electronic configuration. (example K+ and Ar)

Front 196

Isotopes

Back 196

Atoms sharing the same atomic number (Z) but a different number of neutrons.

Front 197

Magnetic Quantum Number
(-1,0,1)

Back 197

The third quantum number. Designated by ml, it describes a particular orbital within a subshell where an electron is very likely to be found. The possible values for ml are integers in the -l to l range, including 0

Front 198

Mass number
(p&n)

Back 198

Sum of the protons and neutrons in an element, often denoted by the letter "A"

Front 199

Neutron

Back 199

A subatomic particle with zero electric charge that is slightly heavier than a proton

Front 200

Neucleus
(p&n = +)

Back 200

The dense, positively charged center of an atom containing its protons and neutrons

Front 201

Orbital
(e-)

Back 201

A three-dimensional region about the nucleus where a rapidly orbiting electron is likely to be found. Each orbital has a unique assignment of values for the n, l and m1 quantum numbers

Front 202

Paramagnetic
(unpaired e-)

Back 202

An atom or a substance that contains unpairs electrons and is consequently attracted by a magnet

Front 203

Pauli exclusion principle

Back 203

No two electrons in an atom can have the same set of four quantum number values

Front 204

Photon
(e=hf)

Back 204

A unit of energy in the form of light equal to hf, where h is Planck's constant and f is the frequency of radiation

Front 205

Principle quantum number
(1st quantum #)

Back 205

First quantum number. Designated by the letter n, it takes on any positive integer value and describes and electron's energy level. An electron with a higher n value is at a higher energy state

Front 206

Proton
(+)

Back 206

A subatomic particle with a charge of +1 and mass of 1.0073 amu

Front 207

Quantum mechanics

Back 207

Study of physics at the atomic level where energy is quantized in discrete, rather than continuous, levels

Front 208

Quantum numbers
(4#'s)

Back 208

A set of four numbers used to describe an electron's energy state(position and energy)

Front 209

Spin Quantum Number

Back 209

The fourth quantum number. Designated by ms, it specifies an electron's intrinsic spin value or angular momentum in an orbital. Since there can be no more than two electrons per orbital, the value of ms can only be +1/2 or -1/2

Front 210

Valence electrons

Back 210

The electrons occupying the outermost electron shell of an atom that participates in chemical bonds. Atoms with the same number of valence e's usually have similar properties

Front 211

Alkali Metals
(1A)

Back 211

The highly reactive elements found in group 1A

Front 212

ALkaline Earths
(2A)

Back 212

Elements found in Group IIA

Front 213

Atomic radius

Back 213

The distance measured either between the nucleus and outermost electron or by the sparation of the two nuclei in a diatomic element.

Decreases from left to right and bottom to top

Related to EA

Front 214

Effective Nuclear Charge

Back 214

The resulting positive nuclear charge on outer electron senses after accounting for the shielding effect of inner core electrons.

Increases from left to right and bottom to top

Related to atomic radius

Front 215

Electron affinity

Back 215

The energy released when an atom or ion in the gaseous state gains an electron.

Increases from left to right and bottom to top

Related to atomic radius

Front 216

Electronegativity

Back 216

A measure of an atom's ability to pull electron density toward itself when involved in a chemical bond.

Increses from left to right and bottom to top

Related to atomic radius

Front 217

Free Radical

Back 217

An atom or molecule that has an unpaired electron in its outermost shell.

Front 218

Halogens

Back 218

Elements found Group VIIA

Front 219

Ionization Energy

Back 219

The amount of energy required to remove an electron from orbit about a gaseous atom into free space.

Increses from left to right and bottom to top

Related to atomic radius

Front 220

Metalloids

Back 220

B, Si, Ge, As, Sb, Te and Po are metalloids and have properties that are in between those of metals and nonmetals

Front 221

Metals

Back 221

Elements that are characteristiclly electropositive, malleable, and ductile. These elements tend to be found on the left side of PT, lustrous and have relatively low ionization energies and electron affinities

Front 222

Noble Gas

Back 222

Inert elements natuarlly existinf in a gaseous state that comprise Group VIII

Front 223

Nonmetals

Back 223

Elements that have characteristically high electronegativity, ionizatiion energy and electron affinity. These elements tend to be found on the right side of PT and are poor conductors of electricity

Front 224

Transition metals

Back 224

The elements found in the B Groups of PT. These elements contain partially filled d subshells

Front 225

Bond energy

Back 225

The energy required to break one mole of a chemical bond; bond enthalpy

Front 226

Covalent bond

Back 226

A chemical bond formed when atoms share bonding electron pairs

Front 227

Dipole-dipole interactions

Back 227

Thyp if intermolecular force in which opposite poles of neighboring dipole molecules are drawn together

Front 228

Dipole moment

Back 228

The product of the amount of partial charge oa either end of a molecule's dipole multiplied by the distance between them

p=qd
where p is the dipole moment, q is the partial charge and s is the distance

Front 229

Dispersion forces

Back 229

A weak intermolecular force prevalent in nonpolar covalent molecules caused by transient dipole-induced attractions: London forces

Front 230

Formal charge

Back 230

The charge assigned to an atom in a molecule or polyatomic ion calculated by the formula: #valence e - #1/2 bonding e - # nonbonding e.

Molecules containing atoms with lower formal charges tend to be more stable

Front 231

hydrogen bonding

Back 231

Very stron intermolecular force where a H covalently bound to N, O or F is attracted to anouther N, O or F

Front 232

Intermolecular forces

Back 232

The attractive and repulsive forces between neighboring molecules

Front 233

Ionic bond

Back 233

A type of chemical bond in which there is a complete transfer of valence electrons to form positive and negative ions that are subsequently bound by eletrostatic forces; strong attractions holding ions together in an ionic compound

Front 234

Lewis structure

Back 234

A method using lines and dots to represent valence electrons and shared pairs

Front 235

Molecular orbital

Back 235

The region in a molecule where atomic orbitals overlap, resulting in either a stable low-energy bonding orbital or an unstable high-energy antibonding orbital

Front 236

Nonpolar covalent bond

Back 236

A type of covalent bond between atoms with the same electronegativities resulting in an even distribution of electron density along the bond

Front 237

Octet Rule

Back 237

A rule stating that atoms- (except Be, H and B)tend to react in order to form a complete octet of valence electrons.

Front 238

Polar covalent bond

Back 238

A type of covalent bond between atoms with different electronegativities that results in an unequal sharing of electron pairs, giving the bond partial positive and negative poles

Front 239

Resonance structures

Back 239

Alternate lewis structures of the same molecule that show the delocalization of electrons within that molecule; Lewis structures that contribute to a resonance-stabilized system. Resonance structures have the same atomic connectivity but differ in the distribution of electrons

Front 240

VSEPR

Back 240

The acronym for Valence Shell ELectron Pair Repulsion theory, which states that the 3-dimensional molecular geometry about some central atom us determined by the electronic repulsions between its bonding and nonbonding pairs

Front 241

Combination reaction

Back 241

A rxn in which two or more reactants combine to form a product.

A + B -> C

Front 242

Decomposition reaction

Back 242

A chemical reaction in which one substance breaks down into two substances

C -> A + B

Front 243

Disproportionation

Back 243

A redox rxn in which the same species is both oxidized and reduced

Front 244

Double displacement reaction
(metathesis)

Back 244

A chemical reaction in which two different compounds exchange an atom or ion to form two new compounds;
AB + CD -> AC + BD

Front 245

Empirical formula

Back 245

Chemical formula showing the smallest whole number ratio of atoms in a compound

Front 246

Formula weight

Back 246

The sum of all the masses (in amu) present in one molecule of a molecular compound

Front 247

Limiting reagent

Back 247

The reactant of chemical equation that, given nonstoichiometric amounts, determines that samount of product that can form; the reactant that runs out first

Front 248

Molecular formula

Back 248

A chemical formula showing the actual number of atoms present in a certain compound

Front 249

Molecule

Back 249

The smallest unit of a substance, compossed of two or more atoms joined in covalent bonds, which still retains all the chemical properties of the substance

Front 250

Net ionic equation

Back 250

A representation of a displacment rxn showing only the reactive species and omitting the spectator ions

Front 251

Percent composition

Back 251

The percentages by mass (in amu)of the elements making up a compound

Front 252

Percent yield

Back 252

A ratio (calculated as a percentage) of the actual mass of product yielded to the theoretical yield of product mass

Front 253

Single displacement reaction

Back 253

A chemical reaction in which an atom or ion of one compound is replaced by anouther atom or ion.

A + BC -> B + AC

Front 254

Theoretical yield

Back 254

The expected amount of product yielded in a reaction according to reactants stoichiometry

Front 255

Activation energy

Back 255

Often denoted Ea, it is the energy barrier that must be overcome for a reaction to proceed

Front 256

Chemical kinetics

Back 256

The study of rxn rates and the factors that affect them

Front 257

Collision theory of chemical kinetics

Back 257

Theory stating that the rate of a rxn is directly proportional to the number of collisions that take place between reactants per second.

Front 258

Equilibrium

Back 258

A dynamic point reached by a reversible rxn in which the rate of the forward reaction is equal to the rate of the reverse reaction. There is no net change in the concentrations of the products and reactants being formed

Front 259

Equilibrium Constant

Back 259

A ratio of the concentrations of the products to the concentrations of the reactants at the point of equilibrium, where each reactant and product in the expression is raised to the power of its stoichiometric coefficient. Commonly denoted by Keq

Front 260

Le Chatelier's Principle

Back 260

The fact that when a system in equilibrium is placed under one of several stressors, it will react in order to regain equilibrium

Front 261

Rate-determining step

Back 261

The slowest step in a reaction mechanism that dettermines the overall rate of the reaction.

Front 262

Rate Law

Back 262

An experimentally determined mathematical expression showing the rate of reaction as a function of the concentration of its reactants

Front 263

Reaction mechanism

Back 263

A "play by play" showing the individual steps of a rxn, including the formation and destruction of any rxn intermediates that may occur

Front 264

Reaction order

Back 264

The sum of the exponents in a rate law, where each exponent provides the reaction order with respect to its reactant

Front 265

Reaction Quotient

Back 265

A ratio of the concentrations of the products to the concentration of the reactants at any point during the reaction aside from equilibrium, where each reactant and product in the expression is raised to the power of it stoichiometric coefficient. Commonly denoted by Q.

Front 266

Reaction rate

Back 266

The measure of how quickly reactants are consumed and products are formed

Front 267

Reversible Reaction

Back 267

A process that will proceed bidirection ally to form both product and reactant

Front 268

Transition state

Back 268

A high energy complex in which old bonds are partially broken and new bonds are partially formed. Charges existing only prior to or after the formation of the complex are designated as partial charges

Front 269

Adiabatic Process

Back 269

A process that occurs in which no heat is transferred to or from the system by its surrounds

Front 270

Closed system

Back 270

A system that allows for the exchange of energy but not matter across it boundaries

Front 271

Constant-volume calorimeter
"Bomb"

Back 271

An apparatus commonly referred to as a "bomb calorimeter" used to measure the amount of heat absorbed or released following a reaction

Front 272

Endothermic Reaction

Back 272

A reaction that proceeds with the net absorption of energy(heat) from the surroundings

Front 273

Enthalpy

Back 273

The total heat content of a system at constant pressure, commonly denoted by "H"

Front 274

Entropy

Back 274

The chaos or randomness of a system, often denoted by the letter "S". Change is S represents the change in entropy following a reaction

Front 275

Exothermic

Back 275

A reaction that proceeds with the net release of energy (heat) into the surroundings

Front 276

Gibbs free energy

Back 276

The energy of a system available to do work

Front 277

Gibbs Free Energy

Back 277

The energy of a system available

Front 278

Gibbs-Helmholtz equation

Back 278

∆G = ∆H - T∆S

Front 279

Heat

Back 279

A transferable energy usually in the form of kinetic energy of molecules

Front 280

Hess's Law

Back 280

A statement that the enthalpy change of an overall reaction is equal to the sum of the standard heats of formation of the products minus the sum of the standard heats of formation of the reactants

Front 281

Isobaric Process

Back 281

A process that occurs at a constant pressure

Front 282

Isochoric Process

Back 282

A process in which volume remains constant and no net pressure-volume work is done

Front 283

Isolated system

Back 283

A system that can exchange neither energy nor matter with its surroundings

Front 284

Isothermal process

Back 284

A process that occurs in which the system either gains or loses energy in order to maintain a constant tempreture

Front 285

Law of conservation of energy

Back 285

Law stating that energy cannot be created nor destroyed but only transferred and transformed

Front 286

Open system

Back 286

A system that allows for the exchange of energy and matter across its boundaries

Front 287

SPecific heat

Back 287

The amount of heat required to raise one gram of a substance by 1 degree Celcius; heat capacity

Front 288

Spontaneous reaction

Back 288

A rxn that will proceed or occur on its own without input of energy from its surroundings

Front 289

Standard Free energy

Back 289

The value of ∆G as calculated under standard conditions:

1 atm and 0 Kelvin

Front 290

Standard heat of formation

Back 290

Measure of the heat absorbed or released when a substance is formed from its naturally occuring elements. Often denoted by ∆Hf

Front 291

Standard heat of reaction

Back 291

The change in enthalpy of a rxn at Standard temp and presure

Front 292

State function

Back 292

A function that depends only on the initial and final states of a system, not on the path in between

Front 293

System

Back 293

The part of the universe under consideration that is separated by some real or imaginary boundary from its surroundings

Front 294

Avogadro's priciple

Back 294

Principle stating that when different gases of equal volumes are at identical tempretures and pressures the contian equal numbers of molecules

Front 295

Boyle's Law

Back 295

At a constant tempreture, the volume of an ideal gas is inversly proportional to its pressure

V α 1/P

Front 296

Charles and Gay-Lussac Law

Back 296

At a constant pressure, that volume of an ideal gas is directly proportional to its tempreture. V α T

Front 297

Diffusion

Back 297

Passive transport of a gas or solute throughout a medium by means of random motion

Front 298

Effusion ☺

Back 298

The movement of gas through a small opening into an area of lower pressure.

(hee hee)

Front 299

Graham's Law

Back 299

Law stating that the rate at which two different gases effuse/diffuse is inversly proportional to the square root of their molecular weight.

R1/R2 = √(MM2/MM1)

Front 300

Henry's law

Back 300

The partial pressure of a gas dissolved in a solution is directly proportional to the partial pressure of this gas above the solution

Front 301

Ideal Gas

Back 301

A hypothetical gas whose particles would occupy zero volume volume and have no attractive intermolecular forces

Front 302

Ideal Gas Law

Back 302

A unification of Boyle's Law, Charles' Law, and Avogadro's Principle into the formula that describes the behavior of ideal gases: PV = nRT

Front 303

Kinetic Molecular Theory of Gases

Back 303

A series of ideas used to account for the behavior of ideal gases. The theory describes gas as volumeless particles in constant, random motion that exhibit no intermolecular attractions and undergo completely elastic collisions with each other and their container walls

Front 304

Partial Pressure

Back 304

The pressure contribution of single gas in a container holding a mixture of gases, as given by the equation

Pa = P(total)Xa

where Xa is the mole fraction of gas "a" and P(total) is the total pressure of the mixture

Front 305

STP

Back 305

Standard tempreture and pressure

273 K - 0 Celcius
1 amt - 760 torr

Front 306

Vapor Pressure

Back 306

The partial pressure of a vapor when it is in equilibrium with its solid or liquid phase

Front 307

Azeotrope

Back 307

A liquid mixture of two or more substances that has a constant boiling point greater than or less that the boiling points of its constituients. The vapor of this unique mixture has the same composition as the liquid state making it difficult to separate the constituients

Front 308

Colligative properties

Back 308

The properties of solutions - such as vapor pressure lowering, freezing point depression, boiling point elevation and osmotic pressure - that are affected only by the number of solute particles dissolved and not their chemical identities

Front 309

Phase diagram

Back 309

A pressure verses tempreture plot showing the conditions under which a substance exists in equalibrium between different phases or in which the substance exists in pure phase

Front 310

Raoult's law

Back 310

The vapor pressure of one component above a solution is proportional to the mole fraction of that component in the solution.

Pa = XaP(total)

Front 311

Triple point

Back 311

A point on a phase diagram at which a substance exists in equilibrium between all three phases

Front 312

Aqueous Solution

Back 312

A solution containing water as its solvent

Front 313

Common ion effect

Back 313

The molar soluability of one salt is reduced when anouther salt , having a common ion is brought into the same solution.

Front 314

Concentration

Back 314

A ratio of the amount of solute to the amount of solution

solute/solution

Front 315

Electrolyte

Back 315

A compound ionizing in water that is capable of conducting electricity in that solution

Front 316

Ion

Back 316

A single or polyatomic particle with an electric charge

Front 317

Ion product

Back 317

The product of the molar concentrations of dissociated ions in solution at any point in the rxn other that equilibrium or saturation, where each ion is raised to the power of its stoichiometric coefficient, Denoted IP

Front 318

MolALity

Back 318

Concentration of a solution calculated by

(mole solute) / (1kg solvent)

Front 319

MolARity

Back 319

concentration of a solution calculated by
(mole solute)/(L solution)

Front 320

MolAR solubility

Back 320

The molar amount of a solute that can dissolve in 1 L of solvent untill equilibrium saturation is reached

Front 321

Normality

Back 321

the gram equivalent of solute per liter of solution, often denoted by N

Front 322

Solubility

Back 322

A ratio that measures how much solute can dissolve in a solvent at a given tempreture, expressed in units of
(g solute)/(100g solvent)

Front 323

Solubility product constant

Ksp

Back 323

The product of the molar concentrations of dissociated ions in solution at saturation, where each ion is raised to the power of its stoichiometric coefficient

Ksp

Front 324

Solute

Back 324

A compound, commonly a solid, dissolved in a solvent to create a solution

Front 325

Solution equilibrium

Back 325

When a solute is dissolved in a solvent it will dissociated untill reaching an equilibrium point at which the rate of dissociation = the rate of percipitation of the solute reguardless of any additional solute introduced into the mixture

Front 326

Solvation

Back 326

A cagelike network of solvent molecules that forms around a solute in a solution

Front 327

Solvent

Back 327

A medium, commonly a liquid into which a solute is dissolved to create a solution

Front 328

Acid dissociation constant

Ka

Back 328

An equilibrium expression used to measure weak acid strength, given by the ratio of the products' molar concentrations to the product of the reactants' molar concentrations, with each term raised to the power of its stoichiometric coefficient

Ka

Front 329

Amphoteric

Back 329

A secies capable of reacting with either an H+ or OH- therby behaving as either an acid or a base;

amphiprotic

Front 330

Arrhenius Definition

Back 330

A definition of acids as producers of H+ and bases as producers of OH- in aqueous solution

Front 331

Bronted-Lowry Definition

Back 331

Common definition of acids as proton (H+) donors and bases as proton acceptors

Front 332

Buffer

Back 332

A solution containing a weak acid or base coupled with its conjugate salt, acting to prevent changes to the solutions pH upon the addition of acidic or basic substances

Front 333

Conjugate acids and bases

Back 333

A systematic pairing of a depronated specie (base) with its pronated form (conjugate acid).
Conjugates appear on opposite sides of a chemical equation

Front 334

Diprotic base

Back 334

A base that can accept two moles of H+ per mole of itself

(SO4)2-

Front 335

Equivalence Point

Back 335

The point in a titration at which an equimolar amount of titrant has been added to the unknown solution

Front 336

Half-Equivalence Point

pK=pH

Back 336

The point in titration at which exactly half the molar equivalence of reactant is consumed by the titrant being added. At this point in an acid-base titration, the pK of the unknown solution is revealed. pK = pH of the solution at half-equivalence point during the titration

Front 337

Henderson-Hasselbach equation

Back 337

An equation commonly used in titration-based problems that related the pH or pOH of a solution to the pK and the ratio of the dissociated species.

pH= pKa + log ([A-]/[HA])

Front 338

Indicator

Back 338

A chemical species that changes color when undergoing dissociation. Indicators are used to signal the end point of a titration

Front 339

Lewis definition

Back 339

A definition of acids as electron-pair acceptors and bases as electron-pair donars

Front 340

Neutralization reaction

Back 340

A rxn in which an acid and a base are combined to form water and a salt

Front 341

pH

Back 341

Scaled value used to measure the acidic strength of a solution, calculated by taking the negative log of the H+ molar concentration of a solution

pH =-log [H+]

Front 342

pl

Back 342

The pH of a molecule at which it contains no net electric charge:

ISOELECTRIC POINT

Front 343

Strong Acids

Back 343

An acid that will completely dissociate in aqueous solution.

HCL, HI, HCLO4

Front 344

Titration

Back 344

An analytical procedure in which a solution of know concentration is slowly added to a solution of unknown concentration to the point