The group on the periodic table that would have 0 electronegativity due to the fact that their valence shell is full, i.e, have a full octet would be the inert or noble gases. They have a total of 8 electrons in their valence shell and are thus inert and cannot strongly attract electrons toward itself, from neighbouring atom electrons as it does not need to.
A solid is hard and the molecules are packed together, a liquid can move around freely because the molecules aren't as packed together :)
<span>There is a direct correlation between the period number and the energy level for valence electrons. For example, the H and He elements, in period 1, have their outer electrons in the energy level "1". This continues down the rows: all the elements in period 2 have their principal energy level as n = 2, period 3 has n = 3, and so on.</span>
3 mol H₂ → 2 mol NH₃
5 mol H₂ → x mol NH₃
x=2*5.0/3=3.3
n(NH₃)=3.3 mol