A change in temperature is a sign that a chemical reaction has occurred. This occurs in an endothermic reaction. An endothermic process is any process which requires or absorbs energy from its surroundings, usually in the form of heat. It may be a chemical process, such as dissolving ammonium nitrate in water, or simply the melting of ice cubes.
Hopefully im not too late :/
Answer:
plum pudding model .
Explanation:
the electrons were 'like plums embedded in a pudding'. Also called the Raisin Bread Model.