22. Which energy level has the highest amount of energy? A. First
B. Second
C. Third
D. Fourth

Iknow the answer is a but i don't know why

The chemical equation below shows the reaction of sodium (na) and chlorine (cl) to form sodium chloride (nacl). 2na + cl2 → 2nacl in this equation, which of the following is a reactant? i. sodium ii. chlorine iii. sodium chloride

How do you know when a chemical reaction has occurred