To gain a complete octet is Sodium likely to gain
or lose electrons?

A neutral sodium atom is likely to achieve an octet in its outermost shell by losing its one valence electron. The cation produced in this way, Na+, is called the sodium ion to distinguish it from the element. The outermost shell of the sodium ion is the second electron shell, which has eight electrons in it.

Explanation:

in chemistry, a solution’s concentration is how much of a dissolvable substance, known as a solute, is mixed with another substance, called the solvent. the standard formula is c = m/v, where c is the concentration, m is the mass of the solute dissolved, and v is the total volume