Energy changes and chemical reactions

in these reactions _______ energy is required to break the bonds of the ______ than is released when products form

more, reactants

_______ can affect the rate of reaction because at higher _______ particles move faster

temperature, temperature

_________ area can affect the rate of a reaction

surface area

most chemical reactions release more energy than they ________

absorb

breaking a chemical bond __________ energy from the surroundings

absorbs

_________ is the minimum amount of energy that is needed to start a chemical reaction

activation energy

minimum amount of energy needed to start a chemical reaction

activation energy

substance that increases the reaction state by lowering the activation energy of a reaction

catalyst

a _____ increase reaction rate by lowering the ________ energy of a reaction

catalyst, activations

a catalyst is not itself permanently ______ during a chemical reaction

changed

energy released in a chemical reaction comes from _________ that is contained in chemical _____

chemical energy, bonds

at higher temperatures particles _______ more often

collide

an increase in _______also increases reaction rate because there are more particles to ______ with each other

concentration, collide

the energy in chemical bonds and the energy absorbed or released is always _______

conserved

_____ reactions are chemical reaction that absorb thermal energy

endothermic

chemical reactions that absorb thermal energy

endothermic

they also collide with more _____

energy

all reactions require ______ to start the breaking of ______

energy, bonds

an ________ is a catalysts that speeds up chemical reactions in living cells

enzyme

catalyst that speeds up chemical reactions in living cells

enzyme

______ reactions are chemical reactions that release thermal energy

exothermic

chemical reactions that release thermal energy

exothermic

surface area is the amount of ______ outer area of a solid

exposed

chemical reactions occur ______ if the particles _______ more often or if the particles move _________ when they collide

faster, collide, faster

the activation of some reactions is so ________ that more energy is needed to start the reaction

high

_______ surface area increases the rate of reaction because more _______ on the surface of a solid come in contact with the _____ of another substance

increase, particles,particles

substance that slows down or even stops a chemical reaction

inhibitor

substances called ______slow down or stop a chemical reaction

inhibitors

in these reactions ______ energy is required to break the bonds of the ________ than is released when products form

less, reactants

the activation energy of some reaction is so _____ that enough energy to start the reaction comes from the ________

low, surroundings

for gases increased _______ pushes particles closer together and more _______ occur

pressure, collisions

catalysts also no not change the ________ or the products of the reaction

reactants

some chemical reactions absorb more energy than they ________

release

forming a chemical bond _________energy to the surroundings

releases

the rate of a reaction is the _____ at which it occurs

speed

some chemical reactions do not _______ by themselves

start