Understanding Physical and Chemical Changes
Physical and chemical changes are two fundamental concepts in science that describe how substances behave and transform. Here’s a detailed breakdown of their differences:

Physical Change
- A physical change involves a change in the form or appearance of a substance without altering its chemical composition.
- The substance retains its original properties and can often be reversed.

Examples of Physical Changes:
- **Melting Ice:** Ice melts into water, but the chemical structure (H₂O) remains the same.
- **Dissolving Sugar in Water:** Sugar dissolves, creating a solution, but it can be recovered by evaporation.

Chemical Change
- A chemical change, on the other hand, results in the formation of one or more new substances with different properties.
- This change usually cannot be reversed easily.

Examples of Chemical Changes:
- **Burning Wood:** Wood burns to produce ash, smoke, and gases, altering its chemical structure.
- **Rusting of Iron:** When iron reacts with oxygen and moisture, it forms rust (iron oxide), a new substance.

Key Differences:
- **Reversibility:** Physical changes are generally reversible, while chemical changes are not.
- **Substance Identity:** Physical changes do not change the substance's identity, whereas chemical changes create new substances.
Understanding these changes helps us appreciate the various transformations that matter undergoes in our daily lives!

Physical changes affect the physical properties of a substance, such as its shape, size, or state, but the substance itself remains the same.
Example - Freezing water

Chemical changes occur when one or more substances are combined to create a new substance with different properties.
Example - Burning of paper