Are there any borderline elements, that is, do any of elements appear to have properties of both groups

elements: : aluminum, carbon, iron, magnesium, silicon, sulfur, tin, zinc

You use the atomic number to find out how many protons and neutrons there are in the atom. you use the atomic mass to find out how many protons and electrons there are in the atom. 

#2- the hno3 has a h+ ion and the naoh has an oh- ion

The answer your looking for is that both valance is 1 because they are both in the alkali group