Compounds
Science: KS3, topic 2.1.7
Compounds
Atoms of different elements can be combined together to create compounds. Compounds have formulae that are made by combining the chemical symbols of the elements that combine to make them.
Different compounds
- Combining different atoms creates different compounds. There are a lot of combinations that can be created.
- A compound contains at least 2 different elements.
Lego
- Compounds are a bit like Lego.
- Different combinations of bricks result in different models.
- Similarly, different combinations of atoms result in different compounds.
E.g. sodium oxide
- Combining sodium (Na) atoms and oxygen (O) atoms gives sodium oxide.
- We can represent this compound by combining the chemical symbols of the 2 elements (Na and O) to create the chemical formula Na2O.
Test yourself on Compounds
What is the chemical formula for sodium oxide?
Select the true statement in each pair.
Chlorine atoms join together to form Cl2. Why is Cl2 not classed as a compound?