What must be true of the net charge for any sample of sodium chloride

Zero (0)

Explanation:

Since Na^+ has a charge of +1 and Cl^- has a charge of —1 in NaCl

Then the net = +1 —1 = 0

it's filtration, but this is an assumption so my apologies if i got this

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