KS3 Science Revision

Atoms are tiny building blocks which make up everything. Atoms are made up of a nucleas, containg protons and nutrons, which is surrounded by electrons. The atoms in a particular element are the same as each other. For example Oxygen is made up of 2 oxygen atoms.

 

Compounds are substances that contain two or more different atoms which have been chemically bonded. Carbon Dioxide is a compound. Mixtures are like compounds, but have not been chemically connected. Mud is a mixture of water and soil. Sea water is a mixture of salt and water