it is an organ. the main organ in the body. I wish your question was a little more clear, like multiple choice would be very helpful to what my choices are.
Activation energy is required to start a chemical reaction. Activation energy is the energy needed to allow the reactant to react. Activation energy is measured in Joules (J).
1. climate change (C)
2. use more nonrenewable resources (A)
3.by polluting near by streams with pesticides and herbicides (B)