How do amines form salts when they react with acids?

Amines form salts through an acid-base reaction facilitated by the presence of a nonbonded electron pair on the nitrogen atom.123

According to the Brønsted-Lowry theory, amines act as bases because they can accept a hydrogen ion ($H^{+}$) from an acidic molecule. During this process, the hydrogen ion adds directly to the nitrogen atom, which utilizes its lone pair of electrons to form a bond.2413

When reacting with strong mineral acids—such as hydrochloric acid ($HCl$), sulfuric acid ($H_{2}S{O}_4$), or nitric acid ($HN{O}_3$)—this reaction is typically vigorous. The resulting product is a salt, which contains a positively charged nitrogen center. This salt formation is reversible; the addition of a strong base, such as sodium hydroxide ($NaOH$), can remove the hydrogen ion and regenerate the original amine.1