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?

Verified step by step guidance

1. Step 1: Identify the characteristics of a chemical change. Chemical changes involve the formation of new substances and are often accompanied by observable phenomena such as gas production, color change, or temperature change.
2. Step 2: Identify the characteristics of a physical change. Physical changes involve changes in the state or appearance of a substance without forming new substances.
3. Step 3: Analyze the given scenario. The formation of bubbles on the surface of the metal suggests the production of a gas, which is a strong indicator of a chemical reaction taking place.
4. Step 4: Consider the dissolution of the metal. If the metal is dissolving and forming a new substance in the solution, this further supports the occurrence of a chemical change.
5. Step 5: Conclude based on the observations. Since the scenario involves gas production and the metal dissolving, it is indicative of a chemical change rather than a physical change.

Key Concepts

Chemical 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.

Physical 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.

Reactivity of Metals with Water

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.