Question

Which changes are physical changes? ( two answers)

1 melting ice to form water
2 burning hydrogen to form water
3 adding sodium to water
4 Boiling water to form steam

Answer 1

The two changes that are physical changes are:

• Melting ice to form water.
• Boiling water to form steam.

Physical changes are transformations in matter that do not alter the chemical composition of substances. In both of these cases, the substances involved (ice and water in the first case, and water in the second case) remain the same chemically; only their physical state changes from solid to liquid or liquid to gas.