Answer:
Mass is a measure of the amount of matter in a substance or an object. The basic SI unit for mass is the kilogram (kg), but smaller masses may be measured in grams (g).
The origin is greek and English
<span>As magnesium has atomic number 12 it's electronic configuration is 2,8,2 in the K,L,M shells.Thus as we can see it has 2 electrons in the outermost shell hence, it has 2 valence electrons.</span>