Chem Ii - Exam I

Front 1

Atomic Number

Back 1

The number of protons in the nucleus of an atom

Front 2

Mass Number

Back 2

The total number of protons and neutrons in the nucleus of an atom

Front 3

Isotope

Back 3

Two atoms that have the same number of protons but different number of neutrons

Front 4

Nuclide

Back 4

Atom's nucleus

Front 5

Nuclear Reaction

Back 5

A reaction that involves changes in the nucleus of an atom

Front 6

Radioactive (nuclear) decay

Back 6

The spontaneous breakdown of an unstable nucleus of an atom

Front 7

Nuclear Stability

Back 7

The ability of a nucleus to stay together and not fall apart

Front 8

Alpha Particle

Back 8

A radioactive particle composed of 2 protons and 2 neutrons

Front 9

Beta Particle

Back 9

A radioactive particle that is identical to an electron but is emitted from an atom's nucleus

Front 10

Positron

Back 10

A radioactive particle that is identical to an electron but has a positive charge

Front 11

Gamma Radiation

Back 11

A very high energy type of radiation that is often emitted from unstable nuclei

Front 12

Ionizing Ability

Back 12

The ability of a subatomic particle to knock electrons off of an atom

Front 13

Penetrating Ability

Back 13

The ability of a subatomic particle to pass through a material

Front 14

Balanced Nuclear Equation

Back 14

An equation that describes the radioactive decay of an unstable nucleus. The total number of protons and neutrons in the reactants must equal the total number of protons and neutrons in the products

Front 15

Zone of Stability

Back 15

The area on a neutron-proton graph where the nuclei are stable and do not emit radioactive particles.

Front 16

Decay Rate

Back 16

A measure of how often an unstable nucleus emits a radioactive particle

Front 17

Half Life

Back 17

The amount of time it takes for 1/2 of a sample of radioactive nuclei to decay = T1/2

Front 18

Mass Defect

Back 18

The difference in mass between the products and the reactants in a nuclear reaction. The products of a nuclear reaction usually weigh less than the reactants

Front 19

Nuclear Binding Energy

Back 19

The energy between the protons and neutrons in a nucleus that binds these particles to each other. The more nuclear binding energy around each particle then the more stable the nucleus.

Front 20

Nuclear Fission

Back 20

The splitting of a large unstable nucleus into two smaller nuclei

Front 21

Chain Reaction

Back 21

This occurs when the neutrons emitted during a fission reaction cause other nearby nuclei to fission

Front 22

Sub-critical Mass

Back 22

A sample of radioactive nuclei that does not contain enough nuclei to sustain a chain reaction.

Front 23

Critical Mass

Back 23

A sample of radioactive nuclei with the number of nuclei required to produce a self sustaining chain reaction.

Front 24

Super-critical Mass

Back 24

A sample of radioactive nuclei that contains too many nuclei resulting in a chain reaction that produces excessive fission reactions = nuclear bomb

Front 25

Nuclear Reactor

Back 25

An electricity producing power plant that uses the heat released from fission reactions

Front 26

Reactor Core

Back 26

The area of a nuclear power plant where the fission reaction occurs

Front 27

Fuel Rods

Back 27

These contain unstable nuclei whose fission results in a significant mass defect. U-235 & Pu-239 serve as the unstable nuclei in the fuel rods

Front 28

Control Rods

Back 28

These absorb the excess neutrons during the fission reaction and slow the chain reaction. They can be cadmium or boron atoms

Front 29

Moderator

- Graphite vs Heavy Water

Back 29

A material that surrounds the fuel rods and serves to slow down the neutrons so the U-235 or Pu-239 can capture them

- Graphite - cheap but if caught on fire can not be put out

- Heavy Water - expensive but will not catch on fire -- US standard

Front 30

Coolant

Back 30

The water in the reactor core that removes the heat released by the fission process

Front 31

Turbine

Back 31

A device that removes the kinetic energy from steam and then powers the generator

Front 32

Generator

Back 32

A device that changes the kinetic energy of the turbine into electricity

Front 33

Nuclear Fusion

Back 33

The combining of two small nuclei to form a larger nucleus

Front 34

∆ G = ∆ H -t∆ S -- Gibbs Free Energy

Back 34

1) -∆H , -∆S = Spontaneous @ low temperatures

2) -∆H , ∆S = Always spontaneous regardless of temperature

3) ∆H , ∆S = Spontaneous @ high temperatures

4) ∆H, -∆S = Never spontaneous

Front 35

Nuclear transformations involve the change of one _____ into another.

Back 35

Element

Front 36

Who observed the first nuclear transformation?

Back 36

Lord Rutherford

Front 37

A device that gives particles very high velocities

Back 37

Particle Accelerator

Front 38

A Geiger counter is filled with ____ gas.

Back 38

Argon

Front 39

A _______ counter involves the release of light by some compound when struck by high energy radiation.

Back 39

Scintillation

Front 40

Ancient artifacts made from ______ can be dated by the C-14 dating method.

Back 40

Wood

Front 41

The C-14 content of the atmosphere up to 10,000 years ago can be estimated by measuring the C-14 content inside ___.

Back 41

Trees

Front 42

I-131 is useful to diagnose and treat diseases of the _____.

Back 42

Thyroid

Front 43

Th-201 is useful to determine the amount of damage suffered by a person who has had a _____.

Back 43

Heart attack

Front 44

Balanced equation showing the decay of C-14

Back 44

C-14 --> N-14 + e- (beta particle)

Front 45

Balance equation showing how C-14 is created in the atmosphere

Back 45

1n + N-14 --> C-14 + 1p

Front 46

Speed of Light Constant

Back 46

3 x 10^8 m/sec

Front 47

System

Back 47

The chemical reaction on which we are focused

Front 48

Surroundings

Back 48

The space around the chemical reaction on which we are focused

Front 49

Energy

Back 49

Anything that has the ability to do work

Front 50

Law of Conservation of Energy

Back 50

The total amount of energy in the universe remains constant. Energy can change location or energy can change form

Front 51

Work

Back 51

The movement of an object against an opposing force

Front 52

Expansion Work

Back 52

The work done by a gas on nearby objects as gas expands

Front 53

Heat

Back 53

The type of energy that naturally moves from a warm object to a cooler object

Front 54

Temperature

Back 54

A measure of the motion or kinetic energy of the atoms in a material

Front 55

Calorimetry

Back 55

The science of measuring amounts of heat gained or lost by compounds

Front 56

Specific Heat

Back 56

The amount of heat needed to raise the temperature of 1 gram of material by 1 Celsius.

Water Cp = 4.18 J/gdegC

Front 57

Calorimeter

Back 57

A devise in which the heat needed to raise the temperature of a calorimeter by 1 Celsius

Front 58

Heat of Combustion

Back 58

The amount of heat released when 1 gram of a material is burned

Front 59

Enthalpy

Back 59

The heat stored in a compound

Front 60

Standard states

Back 60

The form of a compound under standard room conditions, 1 atm and 25C

Front 61

Standard Heat of Formation

Back 61

The amount of heat gained or released when 1 mole of a compound is synthesized from the elements in their standard states

Front 62

Hess's Law

Back 62

The heat absorbed or released during a complex chemical reaction can be calculated by breaking the complex reaction down into a series of simple reactions. The heat absorbed or released by the complex reaction is the sum of the heats absorbed and released during simple reactions

Front 63

Entropy

Back 63

The amount of disorder in a group of molecules

Front 64

Second Law of Thermodynamics

Back 64

During a spontaneous chemical reaction the total entropy of the universe increases

Front 65

Free Energy

Back 65

Energy not contained with any atoms or molecules

Front 66

Spontaneous Reaction

Back 66

A chemical reaction that occurs on its own without any outside influence