What are at least two things that atoms/molecules must do in order to react in a chemical reaction ? think similar to legos

How much energy is made when a pice of wood burns. how do you know

Asap! will give brainiest when a heat wave strikes a region causing more people to run air-conditioning units, electrical demand increases. what needs to be done to meet this increased demand? raising the control rodslowering the control rodsremoving the control rods

What type of reaction fuels the processes seen here?