What interests you about science?

One of the great things about science is that we are constantly learning new things about the world around us. There's actually something called fact decay where over time more and more of what was considered a fact is disproven or modified. It's also amazing how quickly science is turned into technology

Explanation:

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