What is the oxidation number of s in li2so4?

S = +6

The oxidation number of a free element is always 0.The oxidation number of a monatomic ion equals the charge of the ion.Fluorine in compounds is always assigned an oxidation number of -1.The alkali metals (group I) always have an oxidation number of +1.The alkaline earth metals (group II) are always assigned an oxidation number of +2.Oxygen almost always has an oxidation number of -2, except in peroxides (H2O2) where it is -1 and in compounds with fluorine (OF2) where it is +2.Hydrogen has an oxidation number of +1 when combined with non-metals, but it has an oxidation number of -1 when combined with metals.The algebraic sum of the oxidation numbers of elements in a compound is zero.The algebraic sum of the oxidation states in an ion is equal to the charge on the ion.

Newton's first law states that every object will remain at rest or in uniform motion in a straight line. Which indicates that A is the right answer!