The factor in determining the average atomic mass of an element is:
B or 2 relative abundance of each isotope because the by looking at how many protons , electrons and neutrons the most isotope is of the element has relative abundance.
163 lb * 1 kg / 2.205 lb * 15.0 mg/kg = 1108.8 mg or about 1.11 g
Group 12 Elements have two valence electrons while Group 13 Elements have three valence electrons.
Number of valence electrons tend to determine factors like reactivity. So elements with different number of valence electrons will have different properties.
That is why G12 and G13 have different properties
