Question

what is activation energy?

Answer 1

We can't draw on this forum but here is a link that shows a diagram.

https://www.google.com/search?q=activation+energy&ie=utf-8&oe=utf-8
The graph is a potential energy diagram. The X line shows the energy at the start, the Y line shows the energy at the end and the space between shows the energy it takes to get from beginning to end. Notice the "hump" in the middle. That is the activation energy; i.e., you need to get OVER that hump or the molecules will not have enough energy for the reaction to take place. An example is a match. That match burning is a spontaneous reaction but we know that the match "does not light itself". However, if we scratch the match on the match cover or on an abrasive surface, the heat energy added from that friction is enough to raise enough of those molecules "over the hump" so the match lights and the energy given off by the burning sustains that burning until all of the chemicals and the wood have been consumed. Hope this helps.