A silvery metal is put inside a beaker of water. Bubbles form on the surface of the metal and it dissolves gradually. (a) Is this an example of a chemical or a physical change?

A chemical change involves a transformation that alters the chemical composition of a substance, resulting in the formation of new substances. This process is often accompanied by observable signs such as color change, gas production, or temperature change. In the context of the question, if the metal reacts with water to form new compounds, it indicates a chemical change.

A physical change refers to a change in the state or appearance of a substance without altering its chemical composition. Examples include changes in state (solid, liquid, gas), shape, or size. In the scenario described, if the metal simply dissolves in water without forming new substances, it would be classified as a physical change.

The reactivity of metals with water varies significantly among different metals. Some metals, like sodium and potassium, react vigorously with water, producing hydrogen gas and metal hydroxides, while others, like gold and platinum, do not react at all. Understanding the reactivity of the specific silvery metal in the question is crucial to determining whether the observed process is a chemical or physical change.