Elements are pure substances that cannot be broken down into simpler substances by chemical means. They are made up of only one type of atom. Examples include oxygen (O), hydrogen (H), and carbon (C).
Compounds are formed when two or more different elements chemically combine in a fixed ratio. They can be broken down into simpler substances by chemical reactions.
Water (H₂O) is a compound because it is made up of two different elements: hydrogen (H) and oxygen (O), combined in a ratio of 2:1.
Here's a simple diagram:
```
O
/ \
H H
```
Explanation:
* The diagram represents a single molecule of water.
* The central red sphere represents the oxygen atom (O).
* The two white spheres represent the hydrogen atoms (H).
* The lines between the spheres represent the chemical bonds holding the atoms together.
Key takeaway: Water is a compound because it is made up of two different elements, hydrogen and oxygen, chemically combined in a fixed ratio. It cannot be broken down into simpler substances by physical means.
