What are the changes that matter undergoes?
Commonly known, matter has three states, namely, gas, liquid and solid. Solid, having a defined volume and shape when heated turns into liquid having a defined volume but no defined shape; liquids when heated turn into gas having no defined volume and no defined shape. There is also a fourth state of matter called plasma, a discussion of that would be out of the scope of this, but as a general intro you can take plasma as the next state of matter after gases, it contains ionized particles of the gas.
