Reactions that give out energy - usually in the form of heat - are called...
Reactions that take in energy from the surroundings - usually in the form of heat - are called endothermic reactions.
What is 'activation energy'?
The overall energy change of a reaction.
The energy needed to start a chemical reaction.
A measure of the strength of a catalyst.
Breaking the chemical bonds in the reactants always [blank_start]requires[blank_end] energy – it is an endothermic process. [blank_start]Making[blank_end] new bonds in the products always releases energy – it is an exothermic process.
If more energy is [blank_start]released[blank_end] when new bonds are made than was absorbed to [blank_start]break[blank_end] the bonds in the reactants, then the reaction is [blank_start]exothermic[blank_end].
If [blank_start]less[blank_end] energy is released when new bonds are made than was absorbed to break the bonds in the [blank_start]reactants[blank_end], then the reaction is [blank_start]endothermic[blank_end].