What defines a salt in chemistry?

A salt in chemistry is defined as a compound that results from the neutralization reaction between an acid and a base. Specifically, this involves the replacement of hydrogen ions in the acid with metal or ammonium ions. When an acid reacts with a base, typically, hydrogen ions (H⁺) from the acid combine with hydroxide ions (OH⁻) from the base to form water, while the remaining components of the acid and base interact to form a salt.

For example, in the reaction of hydrochloric acid (HCl) with sodium hydroxide (NaOH), sodium ions (Na⁺) replace the hydrogen ions in hydrochloric acid, creating sodium chloride (NaCl), a common salt. This concept of replacement captures the essence of how salts are formed in nature and in laboratory settings.

The other options do not accurately define salts. Creating a salt does not involve only carbon and oxygen. While metals can take part in reactions to form salts, the definition isn’t restricted to their direct reaction alone. Additionally, the formation of salts does not occur exclusively from bases; acids are essential in defining their composition through neutralization. This shows that the accepted definition encompasses the broader chemical interactions involved in salt formation.