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!
Answer:

Explanation:
1. Calculate the mass of each element

2. Calculate the moles of each element

3. Calculate the molar ratios
Divide all moles by the smallest number of moles.

4. Round the ratios to the nearest integer
C:H = 1:2
5. Write the empirical formula
The empirical formula is 
C. Gravity acting on the edges of plates and convection in the mantle. So you were correct!
Answer:
I not sure if this is right but maybe b since its particles is more spread out?