Because some machine might not work and would give you the wrong answer
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 :/
The electrons begin at the lowest level, and then fills up until it reaches the highest level, and completely fills the outer shell.
