Because Na has one too many electron to be stable, while Mg has 2. once they loose those electrons, they will be come ion. loosing one electron will give the ion a 1+ charge, and loosing 2 will create a 2+ charge
say, a fridge is a nonliving thing. but its characteristic is that it keeps food cold and hold the food (I think that's what you mean)
The answer is 1. This is because electronegativity increases up a group and across a period. So metals are going to be the least electronegative. 4.0 is the most electronegative element on Paulina's Scale!
Basically a covalent bond would have been made based on two atoms so that it can collaboratively set a trace of more electrons. Although there is no atom that is zero which if it had that then it would considerably be a net charge which it is not from this problem. What makes it unique about it is that this attractive force from creating the bond of the electrons that would be purposely activated that are the nuci for constructive used into two atoms.