Answer:- 21.4 grams of
are formed.
Solution:- The balanced equation is:

From this equation, lithium and nitrogen reacts in 6:1 mol ratio. Limiting reactant gives the theoretical yield of the product. We will calculate the grams of the product for the given grams of both the reactants and see which one of them gives the limited amount of the product. This limited amount of the product will be the theoretical yield.
The molar mass of Li is 6.94 gram per mol and for
It is 28.02 gram per mol. The molar mass of
is 34.83 gram per mol. The calculations for the grams of the product for given grams of both the reactants are shown below:

= 

= 
From above calculations, Li gives least amount of the product. So, 21.4 g of
are formed.
You never told us how old you are so how are we supposed to answer
Atoms are the building blocks of all matter
Im unsure :( maybe try looking up a calorie calculator