Final answer:
The four states of matter are solid, liquid, gas, and plasma. These states differ based on definite shape and volume, with plasma coming in as the fourth state capable of conducting electricity.
Step-by-step explanation:
The four states in which matter exists are: Solid, Liquid, Gas, and Plasma. To clarify, a solid has a definite shape and volume, a liquid has a definite volume but not shape, it takes the shape of its container, a gas has neither definite shape nor volume and it fills the container, and a plasma is like gas but it is ionized and can conduct electricity.
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