Answer: 6.71 g
Explanation: 



Limiting reagent is the reagent which limits the formation of product. Excess reagent is one which is in excess and thus remains unreacted.
Thus lithium is the limiting reagent and nitrogen is the excess reagent.
As can be seen from the balanced chemical equation, 6 moles of lithium reacts with 1 mole of nitrogen to give 2 moles of lithium nitride.
Thus 0.578 moles of lithium react with 0.096 moles of nitrogen.
6 moles of lithium give = 2 moles of lithium nitride
Thus 0.578 moles of lithium give=
of lithium nitride.
Mass of lithium nitride 
Mass of lithium nitride
=
It is more energetically stable to do that. Nature prefers to have a low energy state. If you go somewhere in nature you will usually find a low energy state object or material.
Answer: The study of elements and their compounds and reactions with one another.
Explanation: ACTUAL DEFINITION (Chemistry is the scientific discipline involved with elements and compounds composed of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during a reaction with other substances.)