1. The heat of self-heating rice or self-heating chafing dish comes from chemical reaction. A chemical reaction is a process in which molecules are broken down into atoms, and then the atoms are rearranged and combined into new molecules.

2, in the process of chemical reaction, often appear fever, luminescence, discoloration, precipitation and other phenomena.

3. The essence of chemical reaction is the process that old chemical bonds are replaced by new chemical bonds, which can be subdivided into: combination reaction, decomposition reaction, displacement reaction and metathesis reaction.