16. Using 100 mL of 25% solution, prepare 150 mL of 8% solution. a) what volume should you take from the stock solution?
b) how much water will you need to add?

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