chapter 19 - 20 test

Question 1

a change in which one or more substances are converted into new substances

Answer 1

chemical reaction

Question 2

the starting substances that react in a chemical reaction

Answer 2

reactants

Question 3

new substances produced in chemical reaction

Answer 3

products

Question 4

a way to describe a chemical reaction using chemical formulas and other symbols

Answer 4

chemical equation

Question 5

represent the number of units of each substance taking part in a reaction

Answer 5

coefficients

Question 6

chemical equation with the same number of atoms of each element on both sides of the arrow

Answer 6

balanced chemical equation

Question 7

the amount of a substance that contains 6.02 x 10^23 particle of that substance

Answer 7

mole

Question 8

the mass in grams of one mole of a substance

Answer 8

molar mass

Question 9

occurs when a substance reacts with oxygen to produce energy in the form of heat and light

Answer 9

combustion reaction

Question 10

two or more substances combine to form another substance

Answer 10

synthesis reaction

Question 11

occurs when one substance breaks down or decomposes into two or more substances

Answer 11

decomposition reaction

Question 12

the chemical reaction in which one element replaces another element in a compound

Answer 12

single displacement reaction

Question 13

the positive ion of one compound replaces the positive ion of the other to form two new compounds

Answer 13

double displacement reaction

Question 14

an insoluble compound that comes out of solution during this type of reaction

Answer 14

precipitate

Question 15

loss of electrons

Answer 15

oxidation

Question 16

the gain of electrons

Answer 16

reduction

Question 17

chemical reactions that release energy

Answer 17

exergonic reactions

Question 18

when the energy given off is primarily in the form of thermal energy

Answer 18

exothermic reaction

Question 19

when a chemical reaction requires more energy to break bonds than is released when new ones are formed

Answer 19

endergonic reactions

Question 20

when the energy needed to keep a reaction going is in the form of thermal energy

Answer 20

endothermic reaction

Question 21

the rate at which reactants change into products

Answer 21

reaction rate

Question 22

states that atoms, ions, and molecules must collide in order to react

Answer 22

collision model

Question 23

substance that speeds up a chemical reaction without being permanently changes itself

Answer 23

catalyst

Question 24

used to slow down the rates of chemical reactions or prevent a reaction from happening at all

Answer 24

inhibitors

Question 25

an reaction that can occur in both forward and reverse actions

Answer 25

reversible reaction

Question 26

a state in which forward and reverse reactions or processes proceed at equal rates

Answer 26

equilibrium

Question 27

if a stress is applied to a system at the equilibrium, the equilibrium shifts in the direction that opposes the stress

Answer 27

le chateliers principle

Question 28

the force that causes protons and neutrons to be attracted to each other

Answer 28

strong force

Question 29

the process of nuclei decaying and emitting matter and energy

Answer 29

radioactivity

Question 30

a particle that is composed of two protons and two neutrons

Answer 30

alpha particle

Question 31

a high energy electron that is emitted when a neutron decays into a proton

Answer 31

beta particle

Question 32

the process of changing one element into a different element

Answer 32

transmutation

Question 33

a series of repeated fission reactions caused by the release of additional neutrons in every fission

Answer 33

chain reaction

Question 34

mass energy equation

Answer 34

e = mc^2

Question 35

a radioactive isotope that doctors use to locate molecules in an organism

Answer 35

tracer

Question 36

the amount of time it takes for half the nuclei in a sample of an isotope to decay

Answer 36

half-life