Rawhiya

1. Reactants

What we start with in a chemical reaction.

Example: Vinegar + Baking soda → they are the reactants.

Study: how different reactants combine to start a reaction.

2. Products

What is made at the end of a reaction.

Example: Vinegar + Baking soda → Carbon dioxide gas, water, and salt are the products.

Study: how products are different from reactants.

3. Change

A reaction always involves a change.

Can be:

Color change (copper turns green)

State change (solid → gas)

Gas formation (bubbles)

Study: how to identify if a reaction has happened by spotting changes.

4. Heat/Light

Some reactions give out or take in heat/light.

Exothermic = gives out heat (e.g., burning wood).

Endothermic = takes in heat (e.g., melting ice with salt).

Study: examples in everyday life.

5. New Substance

The most important sign of a reaction → a new substance forms.

New substance has different properties from the reactants.

Example: Rust (iron + oxygen → iron oxide, which is different from iron).

Study: how new substances are formed and why they are not just mixtures.

Key Points.

1. Reactants.

2. Product.

3. Change.

4. Heat/light.

5. New substance.