Salt is the product formed by a reaction in which atoms of an acid are replaced by the atoms of a metal.
a. hydrogen
b. nitrogen
c. oxygen
d. carbon

Salt is the product formed by a reaction in which the hydrogen atoms of an acid are replaced by the atoms of a metal. The salt is formed as a result of the neutralization of the acid by base, that is the metal or positive ion replace the hydrogen ion in the acid. For instance: NaO + H2SO4 = NaSO4 + H2O. In this example, Na [sodium] has replaced the hydrogen in H2SO4, thereby forming the salt NaSO4.

Ch4 is nonpolar and insoluble in water. since all of the hydrogen atoms are evenly spread around the carbon atom even through the c h bond is polar all the poles cancel each other out.