do now explain why the following examples are chemical properties/ changes: 1. a nail is rusty 2. hydrogen…

Brief Explanations:

1. A nail rusting is a chemical change as iron in the nail reacts with oxygen and water in the air to form iron - oxide (rust), a new substance.
2. Hydrogen reacting with oxygen is a chemical change. When hydrogen burns in oxygen, it forms water through a chemical reaction with a change in chemical bonds.
3. Burning wood is a chemical change. Wood, mainly composed of carbon - containing compounds, reacts with oxygen in the air during combustion, producing carbon - dioxide, water vapor, and ash (residue), new substances.

Answer:

1. A nail rusting is a chemical change because iron in the nail reacts with oxygen and water to form iron - oxide (rust), a new substance.
2. Hydrogen reacting with oxygen is a chemical change as hydrogen burns in oxygen to form water through a chemical reaction with bond - breaking and bond - forming.
3. Burning wood is a chemical change as wood reacts with oxygen during combustion to produce carbon - dioxide, water vapor, and ash, new substances.