Today I am going to be telling you about the four states of matter; solid, liquid, gas, and plasma. Solids are hard things like rocks, ice, etc, while liquids are runny substances that you can pour, like water and lava! Gas is kind of hard to explain, but Wikipedia says that it is “an air-like fluid substance which expands freely to fill any space available, irrespective of its quantity”. Plasma is a whole different story. Lightning is made out of plasma and so is the sun! Here are some examples of matter.