chapter 19 - 20 test Flashcards
a change in which one or more substances are converted into new substances
chemical reaction
the starting substances that react in a chemical reaction
reactants
new substances produced in chemical reaction
products
a way to describe a chemical reaction using chemical formulas and other symbols
chemical equation
represent the number of units of each substance taking part in a reaction
coefficients
chemical equation with the same number of atoms of each element on both sides of the arrow
balanced chemical equation
the amount of a substance that contains 6.02 x 10^23 particle of that substance
mole
the mass in grams of one mole of a substance
molar mass
occurs when a substance reacts with oxygen to produce energy in the form of heat and light
combustion reaction
two or more substances combine to form another substance
synthesis reaction
occurs when one substance breaks down or decomposes into two or more substances
decomposition reaction
the chemical reaction in which one element replaces another element in a compound
single displacement reaction
the positive ion of one compound replaces the positive ion of the other to form two new compounds
double displacement reaction
an insoluble compound that comes out of solution during this type of reaction
precipitate
loss of electrons
oxidation
the gain of electrons
reduction
chemical reactions that release energy
exergonic reactions
when the energy given off is primarily in the form of thermal energy
exothermic reaction
when a chemical reaction requires more energy to break bonds than is released when new ones are formed
endergonic reactions
when the energy needed to keep a reaction going is in the form of thermal energy
endothermic reaction
the rate at which reactants change into products
reaction rate
states that atoms, ions, and molecules must collide in order to react
collision model
substance that speeds up a chemical reaction without being permanently changes itself
catalyst
used to slow down the rates of chemical reactions or prevent a reaction from happening at all
inhibitors
an reaction that can occur in both forward and reverse actions
reversible reaction
a state in which forward and reverse reactions or processes proceed at equal rates
equilibrium
if a stress is applied to a system at the equilibrium, the equilibrium shifts in the direction that opposes the stress
le chateliers principle
the force that causes protons and neutrons to be attracted to each other
strong force
the process of nuclei decaying and emitting matter and energy
radioactivity
a particle that is composed of two protons and two neutrons
alpha particle
a high energy electron that is emitted when a neutron decays into a proton
beta particle
the process of changing one element into a different element
transmutation
a series of repeated fission reactions caused by the release of additional neutrons in every fission
chain reaction
mass energy equation
e = mc^2
a radioactive isotope that doctors use to locate molecules in an organism
tracer
the amount of time it takes for half the nuclei in a sample of an isotope to decay
half-life
