What is the rate of reaction? The time it takes for a reaction to occur.

How much energy is needed for a reaction to occur.

Collision Theory

The energy required to break a bond.

With the largest atoms and the smallest number of valence electrons and with the smallest atoms and the greatest number of valence electrons are the most reactive. a. nonmetals; metals b. nonmetals; transition elements c. transition elements; metals d. metals; nonmetals