Which statement is true about acids when in contact with metals?

When acids come into contact with metals, they typically undergo a chemical reaction that leads to the dissolution of the metal. This occurs because acids contain hydrogen ions, which can react with the metal atoms, effectively breaking them down and leading to the release of hydrogen gas. This process is often accompanied by the production of bubbles as the gas is formed.

For instance, when hydrochloric acid reacts with zinc, it dissolves the zinc and produces hydrogen gas, alongside zinc chloride in solution. The ability of acids to react with metals is a fundamental concept in chemistry, illustrating the nature of acid-base reactions.

Other options, while they might have some relevance in specific contexts, are not generally applicable to the interaction between acids and metals. Acids do not typically ignite fires, and while they can release some heat in an exothermic reaction, heat production is not the primary defining characteristic when discussing acids' behavior with metals. Similarly, the color change usually relates to pH indicators rather than the inherent properties of acids reacting with metals. Therefore, the statement that acids dissolve metals accurately captures the essence of their chemical behavior in this context.