Exothermic and Endothermic reactions
Exothermic – the word describes a process that releases energy in the form of heat. Forming a chemical bond releases energy and therefore is an exothermic process. Exothermic reactions usually feel hot because it is giving heat to you.
Endothermic – a process or reaction that absorbs energy in the form of heat. Breaking a chemical bond requires energy and therefore is Endothermic. Endothermic reactions usually feel cold because it is taking heat away from you.