What is the molar ratio of li to n2 in the given reaction? 6li+n2 —> 2li3n

The molar ratio of Li to N2 in the equation 6Li + N2 —> 2Li3N is:

6 moles Li / 1 mole N2

This is because this equation is balanced, and therefore the mole ratios exist just as they do in the reactants of the equation (there are 6 parts Li per each part N2 in order to create the product; this also holds true for moles).

Hope this helps!

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. 

Both models are effective because they show the valence electrons, and these valence electrons indicate the reactivity of an element.