Table salt is formed when an electron is transferred from a sodium atom to a

Table salt has the formula NaCl, where Na is sodium and Cl is chlorine. It is an ionic compound which consists of the cation Na⁺ and the anion Cl⁻. The positive charge in Na means that it readily donates one electron to another. Hence, the proton is transferred from sodium to chlorine.

B? i feel like this is a trick  

Ithink about 50 % of an original isotope's number of atoms remain