In the previous lesson we learnt all about atoms and the elements in the periodic table. In this lesson we learn about elements and compounds which are known as pure substances.
Atoms can chemically combine to form molecules. These molecules are also particles and cannot be separated into their atoms by physical means. In this lesson we study the way in which these particles react by using the particle model of matter.
Using the model of matter we are going to describe the three classic states of matter that we find namely solids, liquids and gases and their behaviours when their states change.
