Terms Chapter 2

Question 1

Atomic Mass

Answer 1

Number of protons and neutrons in an atom

Question 2

Atomic Number

Answer 2

Number of protons in an atom

Question 3

Atom*

Answer 3

Smallest particle of an element

Question 4

Chemical Change

Answer 4

A process by which a substance is changed into a different substance by changing its chemical composition

Question 5

Chemical Energy

Answer 5

Energy produced or absorbed in a chemical reaction

Question 6

Combustion

Answer 6

Burning to produce heat or work

Question 7

Conservation of Matter*

Answer 7

the principle that during an ordinary chemical change, there is no detectable increase or decrease in the quantity of matter; i.e., mass cannot be created or destroyed.

Question 8

Electricity

Answer 8

a fundamental form of energy, consisting of oppositely charged electrons and protons that produce light, heat, magnetic force, and chemical changes

Question 9

Electromagnetic Radiation

Answer 9

Different frequencies of radiation (UV, infrared, gamma, etc.)

Question 10

Electron

Answer 10

a stable subatomic particle with a charge of negative electricity found in atoms.

Question 11

Element

Answer 11

substance that cannot be broken down further by chemical means.

Question 12

Energy*

Answer 12

anything that has the ability to do work

Question 13

Entropy*

Answer 13

a measure of the disorder or randomness of a closed system; more entropy means less energy is available for doing work. The total entropy of an isolated system cannot decrease when the system undergoes a change; it can remain constant for reversible processes, and will increase for irreversible ones.

Question 14

First Law of Thermodynamics*

Answer 14

the total energy of an isolated system remains constant

Question 15

Nuclear Fission*

Answer 15

the division of a nucleus into two or more parts with masses of equal order of magnitude

Question 16

Fuel

Answer 16

any material that involves energy in a nuclear reaction.

Question 17

Nuclear Fusion*

Answer 17

a reaction between two light nuclei resulting in the production of a nuclear species heavier

Question 18

Half-life

Answer 18

the length of time during which, on the average, half of a large number of radioactive nuclides decay

Question 19

Heat

Answer 19

amount of energy travelled from one body to another based on temperature differences

Question 20

Heat of fusion

Answer 20

the heat absorbed by a unit mass of a solid at its melting point in order to convert the solid into a liquid at the same temperature.

Question 21

Heat of vaporization

Answer 21

the heat required per unit mass to change a substance from a liquid to a vapor at its boiling point.

Question 22

Isotope

Answer 22

a radioactive form of an element

Question 23

Kinetic Energy

Answer 23

amount of work that an object can do as a result of motion

Question 24

Mechanical Energy

Answer 24

sum of kinetic and potential energy of an object

Question 25

Molecule

Answer 25

the smallest chemical species of a substance that is capable of stable independent existence.

Question 26

Neutron

Answer 26

particle with the same mass as proton but no electric charge

Question 27

Nonspontaneous process

Answer 27

process that requires energy to continue the process

Question 28

Nuclear energy

Answer 28

energy released through a nuclear reaction (fusion or fission)

Question 29

Nucleus

Answer 29

dense region at center of atom; composed of protons and neutrons

Question 30

Nutrients

Answer 30

chemicals that are needed by living organisms

Question 31

Physical Change

Answer 31

change in matter that rearranges molecules but does not affect their internal structures

Question 32

Potential Energy

Answer 32

stored energy in a system based on its still state (inverse of kinetic energy)

Question 33

Power

Answer 33

rate at which work is done

Question 34

Power Plant (will not need to know this)

Answer 34

a general term for any facility in which some other form of energy (e.g., steam, hydropower) is converted into electrical energy.

Question 35

Propane

Answer 35

a colorless, straight-chain hydrocarbon gas with with formula C3H8 that boils at a temperature of -43.67 degrees Fahrenheit

Question 36

Proton

Answer 36

particle with a positive electric charge

Question 37

Radioactivity

Answer 37

the spontaneous breakdown of an atomic nucleus with the emission of particles and rays

Question 38

Radiocarbon dating (will not need to know this)

Answer 38

a precise method of dating ancient organic artifacts, an important tool in modern archaeology and other branches of science

Question 39

Radioisotope

Answer 39

radioactive isotope

Question 40

Second Law of Thermodynamics*

Answer 40

heat will not flow spontaneously from a cold object to a hot one

Question 41

Spontaneous Process

Answer 41

a process that occurs because of internal properties, with no external forces required to continue the process, although external forces may be required to initiate it

Question 42

Trace Element

Answer 42

any chemical Element that an organism needs very small quantities of to survive