Changes in Materials

1. Physical Changes

Physical changes happen when a material changes its form or appearance but not its basic substance. These changes do not create new materials. For example, when ice melts into water, it is still made of the same substance, just in a different state.

Imagine physical changes as changing your clothes. You are still the same person, but you look different in different outfits.

2. Chemical Changes

Chemical changes happen when a material is changed into a completely new material with different properties. This change involves a chemical reaction. For example, when you mix baking soda and vinegar, they react to form a new substance, carbon dioxide gas.

Think of chemical changes as turning a pumpkin into a carriage. The pumpkin is no longer a pumpkin but has become something entirely new.

3. Melting

Melting is the process where a solid material turns into a liquid when it is heated. For example, when you heat ice, it melts into water. Melting is a physical change because the material is still made of the same substance.

Imagine melting as turning a snowball into a puddle. The snowball is still made of water, just in a different form.

4. Boiling

Boiling is the process where a liquid turns into a gas when it is heated to its boiling point. For example, when you heat water to 100 degrees Celsius, it boils and turns into steam. Boiling is also a physical change.

Think of boiling as making a kettle whistle. The water inside turns into steam, but it is still made of the same substance.

5. Freezing

Freezing is the process where a liquid turns into a solid when it is cooled. For example, when you put water in the freezer, it freezes into ice. Freezing is a physical change because the material is still made of the same substance.

Imagine freezing as turning a puddle into a snowball. The puddle is still made of water, just in a different form.