Describe how a chemical equation is written. Where are the reactants found? What about the products? What separates the two halves of the reaction?

The reactants are listed on the left, and the products are listed on the right. They are separated by an arrow. The arrow can be read as yields, gives, or reacts to produce.

atomic mass = 39

number of neutrons = 20

number of protons= 19

electronic configuration = 1s2 2s2 2p6 3s2 3p6 4s1

the number of electron in first shell = 2

number of electrons in n=3 shell = 8