Question

1. which type of chemical reaction tends to occur on its own, or spontaneously?
2. what is the name for the amount of energy that a reaction needs to get started?
3. how do enzymes act as catalysts in a chemical reaction?

Explanation:

For question 25, spontaneous reactions occur without external influence due to a decrease in free - energy. For question 26, the energy required to start a reaction is called activation energy. For question 27, enzymes lower the activation energy of a reaction, increasing the reaction rate.

Answer:

1. Spontaneous reactions.
2. Activation energy.
3. Enzymes lower the activation energy of a chemical reaction.