How many electrons are in valence shell of a sodium atom before and after reaction with chlorine gas to give sodium chloride NaCl?

Answer 1

Before : One electron in the valence shell After reaction w/ Cl gas: none electron in the valence shell

Answer 2

A sodium atom has 1 electron in its valence shell, while a chlorine atom has 7 electrons in its valence shell. When sodium reacts with chlorine to form sodium chloride, the sodium atom loses its 1 electron to achieve a stable octet configuration, while the chlorine atom gains this electron. The resulting sodium chloride molecule has 8 electrons in the valence shell of the chlorine atom.