Chemistry Midterm

Front 1

a pure substance made of only one kind of atom

Back 1

element

Front 2

a substance made from the atoms of two or more elements that are chemically bonded

Back 2

compound

Front 3

a blend of two or more substances, each of which retains its own identity and properties

Back 3

mixture

Front 4

the smallest unit of an element that retains the properties of that element

Back 4

atom

Front 5

a substance that has a fixed composition (elements and compounds are pure substances, mixtures are not)

Back 5

pure substance

Front 6

matter of uniform composition; has the same proportion of proportion of components throughout (elements, compounds and some mixtures are homogeneous)

Back 6

homogeneous

Front 7

a mixture that is not uniform throughout (some mixtures are heterogeneous)

Back 7

heterogeneous

Front 8

another term for a homogeneous mixture

Back 8

solution

Front 9

matter may be classified into

Back 9

elements, compounds, and mixtures

Front 10

definite volume and definite shape

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solid

Front 11

definite volume and indefinite shape

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liquid

Front 12

neither definite volume nor definite shape

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gas

Front 13

solid to liquid

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melt

Front 14

liquid to gas, happens at all temperatures

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evaporate

Front 15

liquid to gas when reaching boiling point

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boil

Front 16

gas to liquid

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condense

Front 17

liquid to solid

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freeze

Front 18

solid to gas

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sublime

Front 19

gas to solid

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crystallize

Front 20

a characteristic of matter that can be observed or measured without changing the identity of the substance
(EXAMPLES: physical state, boiling point, color, density)

Back 20

physical property

Front 21

a property that relates the ability of a substance to undergo changes that transform it into different substances
(EXAMPLES: flammability, corrosiveness, reactivity with acids)

Back 21

chemical property

Front 22

any change in matter that does NOT change its identity (EXAMPLES: cutting, crushing, melting, boiling, dissolving)

Back 22

physical change

Front 23

a change in which one or more substances are converted into different substances (that have different properties)
(EXAMPLES: burning, rusting, tarnishing, exploding)

Back 23

chemical change

Front 24

another term for a chemical change

Back 24

chemical reaction

Front 25

the substances that react in a chemical change

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reactants

Front 26

the new substances that are formed as a result of a chemical change (or chemical reaction)

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products

Front 27

the closeness of a measurement to its accepted value

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accuracy

Front 28

the closeness of measurements of the same thing made in the same way (the repeatability of a measurement)

Back 28

precision

Front 29

precise? accurate?

A metal cylinder is measured three times: 28.56 g, 28.55 g, 28.55 g.
The cylinder is labeled as having an actual mass of 31.00 g.

Back 29

Measurements are precise but not accurate.

Front 30

when using a measurement instrument (such as a balance, graduated
cylinder or thermometer), measurements should be made to

Back 30

one digit beyond the finest division on the scale

Front 31

the digits written down to record a measurement

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significant figures

(last digit written is uncertain)

Front 32

sig figs

Zeroes at the end of a whole number with no decimal point (such as 1200 cm)
and
Zeroes at the beginning of a decimal fraction (such as 0.054 g)

are...

Back 32

NOT significant

Front 33

sig figs

in multiplication and division...

Back 33

round to the same number of significant figures as the measurement that has the fewest sig figs

Front 34

sig figs

in addition and subtraction...

Back 34

round to the same number of decimal places as the measurement with the least decimal places

Front 35

what is the base unit for each of these fundamental qualities: length, mass, time

Back 35

meter (m), kilogram (kg), seconds (s)

Front 36

combination of fundamental quantities

Back 36

derived quantity

ex: speed, area, volume, density

Front 37

study this chart

Back 37

SI Prefix Abbreviation Meaning
Giga- G Billions (1,000,000,000) 109
Mega - M Millions (1,000,000) 106
Kilo- k Thousands (1,000) 103
Centi- c Hundredths (.01) 10-2
Milli- m Thousandths (.001) 10-3
Micro- µ Millionths (.000001) 10-6
Nano- n Billionths (.000000001) 10-9

Front 38

density=

Back 38

mass/volume

Front 39

the density of a substance is ___

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constant (is always the same regardless of the amount of the substance you have)

Front 40

percent error formula

Back 40

% Error = |Accepted Value – Experimental Value|÷Accepted Value

Front 41

Be familiar with the 5 main ideas of Dalton’s Atomic Theory:

and why b and c are incorrect

Back 41

a. All matter is composed of tiny particles called atoms.
b. Atoms of the same element are identical; atoms of different elements are different.
c. Atoms cannot be subdivided, created or destroyed.
d. Atoms of different elements combine in small whole number ratios to form compounds.
e. In chemical reactions, atoms are combined, separated or rearranged.

Front 42

who discovered the electron and how?

Back 42

Thomson

Passed a current through the gas in a cathode ray tube and saw a beam that was deflected toward a positively charged metal plate. Inferred that the beam was made of negatively charged particles

Front 43

who discovered the nucleus and how?

Back 43

Rutherford

Fired positively charged particles at sheet of gold foil. Found that most passed through, but a small number were deflected. Inferred that most of the atom is empty space with a small, dense positive nucleus.

Front 44

subatomic particles proton, neutron, and electron: location, charge, and relative mass

Back 44

proton: nucleus, +, 1amu
neutron: nucleus, no charge, 1amu
electron: energy levels, -, negligible

Front 45

the number of protons in the nucleus of an atom (the whole # above the symbol on Periodic Table)

Back 45

atomic number

Front 46

the number of protons + neutrons in the nucleus (the decimal # below the symbol on Periodic Table

Back 46

mass number

Front 47

how to find # protons, neutrons, and electrons

Back 47

# Protons = atomic number
# Electrons = atomic number (for a neutral atom)
# Neutrons = mass number – atomic number

Front 48

atoms of the same element that vary in their number of neutrons (they have the same atomic number but have different mass numbers.)

Back 48

isotopes

Front 49

the weighted average of the masses of the known naturally occurring isotopes of the element

Back 49

atomic mass

Front 50

an atom that has lost or gained one or more electron(s) and has an unbalanced electrical charge

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ion

Front 51

positively charged ion [atom has lost electron(s)]

Back 51

cation

Front 52

negatively charged ion [atom has gained electron(s)]

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anion

Front 53

energy in the form of waves that travels through space at a speed of 3.0 X 108 m/s

Back 53

electromagnetic radiation

Front 54

the distance between corresponding points on adjacent waves (distance from crest to crest of a wave)

Back 54

wavelength (λ)

Front 55

the number of waves that pass a given point in a specific time (usually a second) measured in hertz

Back 55

frequency (γ)

Front 56

a bundle or particle of light energy

Back 56

photon

Front 57

Know that the frequency of electromagnetic radiation is inversely proportional to the wavelength as shown in the equation below (where c = speed of light):

Back 57

c = λ•γ
Thus, as the wavelength of the electromagnetic radiation increases, its frequency decreases.

Front 58

the ejection of electrons from the surface of a metal when light of high enough frequency shines on the metal

Back 58

photoelectric effect

Front 59

lowest energy state of an atom (when electrons are in the lowest available energy level

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ground state

Front 60

when an atom has a higher potential energy than its ground state (electrons are in higher energy levels than the ground state)

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excited state

Front 61

a series of bright lines of light of specific wavelengths that are created when the visible light emitted by an excited atom is passed through a prism

Back 61

line emission spectrum

Front 62

the maximum number of electrons that can occupy the outermost energy level of an atom (except for H and He for which the maximum number is 2.)

Back 62

8

also called an octet

Front 63

SUBLEVEL
s
p
d
f

find # of orbitals, max # of electrons, lowest energy level found

Back 63

# OF ORBITALS MAX # OF
ELECTRONS, LOWEST ENERGY,
LEVEL FOUND

1 2 1ST
3 6 2nd
5 10 3rd
7 14 4th

Front 64

An electron will enter an empty orbital in an energy sublevel before entering an orbital that is already occupied by another electron; all unpaired electrons in an energy sublevel will have the same direction of spin.

Back 64

Hund’s Rule

Front 65

No more than two electrons can occupy a space orbital, and these two electrons must have opposite spins

Back 65

Pauli Exclusion Principle

Front 66

It is impossible to simultaneously determine the position and energy (or velocity) of an electron

Back 66

Heisenberg Uncertainty Principle

Front 67

Russian chemist that developed first Periodic Table
•Arranged elements in order of increasing atomic mass
•Placed elements with similar properties in same column
•Left gaps where there were undiscovered elements
•Predicted properties of undiscovered elements based upon
their location in the table (which helped lead to their discovery)
•Problem with table was that a few elements did not fall into
a column with elements of similar properties (a problem that was
corrected when Moseley reorganized the table)

Back 67

Mendeleev

Front 68

Re-organized Mendeleev’s table, placing elements in order of increasing atomic number. This resulted in a change in the location on the table of only a few elements (such as Ar and K switching places), but corrected the problem with Mendeleev’s table because now all elements with similar properties fell into the same column, or group.

Back 68

Moseley

Front 69

what is the Periodic Law?

Back 69

“the physical and chemical properties of the elements are periodic functions of their atomic number.”

What this law is saying is that when the elements are arranged in order of increasing atomic number, there will be repeating patterns of properties

Front 70

Periodic Table:

Group

Back 70

Elements in the same vertical column of Periodic Table
•Groups may be numbered in two ways across the top of Table

a) 1-16
b) IA-VIIIA for representative groups, IB-XB for transition elements
•Elements in same Group have same # of electrons in outer energy level
•Elements in same Group have similar properties

Front 71

Periodic Table:

Period

Back 71

Elements in the same horizontal row of Periodic Table

•Periods are numbered 1-7
•Elements in same period have same number of energy levels
(Period 1 – 1 energy level, Period 2 – 2 energy levels, etc.)

Front 72

1st 92 elements of the periodic table are found in

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nature

(and are called natural elements)

Front 73

the remaining elements not found in nature are ______and often called_______

Back 73

natural elements, transuranium elements

Front 74

metals

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left of zig-zag line

•Solids (except mercury)
•Shiny, malleable, ductile and good conductors
of heat and electricity
•Tend to lose electrons and form cations

Front 75

non-metals

Back 75

right of zig-zag line

•Range from solids to gases (Br only liquid)
•Solids are dull, brittle and poor conductors
•Tend to gain electrons and form anions

Front 76

Have characteristics of metals and nonmetals

Back 76

metalloids

located border zig-zag line

Front 77

Alkali Metals

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Group IA

•Soft, silvery metals (can be cut w/ knife)
•HIGHLY reactive – readily form compounds
•React explosively w/ water, some w/ air
•Not found free in nature (exist in compounds)

Front 78

Alkaline Earth Metals

Back 78

Group IIA

•Silvery metals, harder than Alkali Metals
•Very reactive--readily form compounds
•Not found free in nature (exist in compounds)

Front 79

Halogens

Back 79

Group VIIA

•Highly reactive nonmetals
•Readily form compounds called salts
•Can exist in free state as diatomic molecules
(F2, Cl2, I2, etc.)

Front 80

Noble Gases

Back 80

Group VIIIA

•Have stable configuration of 8 outer electrons
•Chemically inert – do not form compounds
•All are gases

Front 81

Transition Metals

Back 81

Middle Section
(Groups 3-13 or
Groups IB-10B)


•Elements in which electrons are being added to the d-sublevel of the next-to-outer shell
•Have 1 or 2 outer electrons (w/ exceptions)
•Shiny, strong, hard, malleable, ductile, and good conductors of heat & electricity

Front 82

Lanthanides

Back 82

Bottom of Table
Next-to-Last Row

•Elements in which electrons are being added
to the 4f sublevel (2 levels below outer level)
•Metals w/ typical metal properties
•Found in earth’s crust, but not very abundant

Front 83

Actinides

Back 83

Bottom of Table Last Row

•Elements in which electrons are being added
to the 5f sublevel (2 levels below outer level)
•Most are man-made (after uranium)
•Most are radioactive

Front 84

s-Block

Back 84

Groups IA and IIA

Electrons filling the s sublevel of outer energy level

Front 85

p-Block

Back 85

Groups IIIA-VIIIA

Electrons are filling the p sublevel of outer energy level

Front 86

d-block

Back 86

Transition metals

Electrons are filling d-sublevel of the next-to-outer energy level

Front 87

f-block

Back 87

Lanthanides and
Actinides

Electrons are filling the f sublevel two levels below the outer energy level

Front 88

the distance from the nucleus to the outer energy level of an atom

Back 88

atomic radius

Front 89

the distance from the nucleus to the outer energy level of an ion

Back 89

ionic radius

Front 90

the amount of energy required to remove an electron from the outer energy level of an atom

Back 90

ionization energy

Front 91

a measure of the ability of an atom in a compound to attract electrons

Back 91

electronegativity

Front 92

a measure of the readiness with which an element will react with other elements to form compounds

Back 92

reactivity

Front 93

Form ions that are smaller (The atom loses an energy level)

Back 93

Metal Atoms

Front 94

Form ions that are larger (No change in # of energy levels)

Back 94

Nonmetal Atoms

Front 95

Metal atoms release outer shell electrons and become cations surrounded by an “electron sea” in a metallic crystal.

found: Metal elements
Examples: Cu, Zn

Back 95

Metallic bond

Front 96

Transfer of electrons between a metal and a nonmetal. Metal loses electron(s) and becomes a cation; nonmetal accepts electron(s) and becomes an anion.
These oppositely charged ions are strongly attracted to one another and form a crystal lattice.

Compounds of a metal and nonmetal or of a metal and polyatomic ion
Examples: LiCl, Na2SO4

Back 96

Ionic bond

Front 97

Unequal sharing of electrons, usually between two nonmetal atoms. One end of bond is slightly negative (δ-) and the other end slightly positive (δ+)

Compounds of two nonmetals that have relatively large differences in electronegativity.
Examples: H20, CF4
Also found between atoms in a polyatomic ion.
Example: PO4-3, NO3-1

Back 97

Polar Covalent bond

Front 98

only substances that are bonded covalently are composed of:

Back 98

molecules

Front 99

neutral group of atoms that are held together by covalent bonds

Back 99

molecule

Front 100

atoms share two pairs of electrons ( = )

Back 100

double bond

Front 101

atoms share three pairs of electrons (Ξ)

Back 101

triple bond

Front 102

B. Molecular Geometry and Polarity

If the bonds in a molecule are nonpolar, the molecule is

Back 102

nonpolar

Front 103

Molecular Geometry and Polarity

If the bonds in a molecule are polar, the molecule may be either polar or nonpolar depending on the geometry of the molecule. In general, if a molecule is symmetrical (one side a mirror image of the other)it is

Back 103

nonpolar

Front 104

a polar molecule is called a___

Back 104

dipole

Front 105

Remember that all binary compounds end in...

Back 105

–ide

Front 106

Remember to use prefixes with nonmetal-nometal compounds

Back 106

mono -1 di-2 tri-3 tetra-4 penta-5

Front 107

Remember to use ____ in compounds containing Cu, Fe, Cr, Pb, or Sn

Back 107

Roman Numerals

Front 108

6.022 X 1023

Back 108

Avogadro Number

Front 109

name given to the number 6.022 X 1023

(1 mole of an element = 6.022 X 1023 atoms)

(1 mole of a compound = 6.022 X 1023 formula units)

Back 109

mole

Front 110

____ formula tells the smallest whole number ratio of the atoms of the elements that make up the compound

Back 110

empirical

Front 111

tells the kind and number of atoms in a molecule of a compound

Back 111

molecular formula