Question

What must happen before a chemical reaction can begin?
The activation energy must be exceeded.
The activation energy must be reached.
The concentrations of products and reactants must be equal.
The concentration of reactant molecules must be reduced.

Answer 1

The reactants must come into contact? Bonds must be broken? Both? ^^

Answer 2

Before a chemical reaction can start energy must be absorbed by the reactants. The amount that must be absorbed to start the reaction is called the activation energy.

Answer 3

The activation energy must be reached.