The inferior alveolar nerve is the larger branch of the posterior division of the mandibular nerve. The inferior alveolar nerve enters the mandibular foramen in the ramus of the mandible (see the image below) to occupy the inferior alveolar canal in the body of the mandible.
The formula for the compound between Lithium and Sulfur is  Li2S because Lithium has a +1 charge while Sulfur has a -2. So for it to be stable, there needs to be two Lithium atoms attached to one Sulfer.
Yes, there is a difference, and it does matter! The placement of subscripts and coefficients tells you how the substances are put together on the atomic level. Let's look at the first equation: $$ \ce{2Li + S -> Li2S} $$ This one indicates that two moles of lithium combine with one mole of sulfur to form one mole of lithium sulfide. $\ce{Li2S}$ is called a formula unit or empirical formula, and tells you the smallest whole-number ratio of atoms that make up a