Traditionally matter was said to exist in only three common states; solids, liquids and gases. Recently a fourth state called a plasma has been identified, but this form of matter is usually only seen in high energy and high temperatures. Converting matter from one state to another is a physical change. The particles are the same but they simply have different amounts of freedom of motion. Click here to see examples of plasmas. Lightning and the aurora borealis are examples of plasmas.

 

The familiar states of matter are solid, liquid, and gas. The particles in the solid are touching with very little space between them. The particles in a liquid usually are still touching but there are some spaces between them. The gas particles have big distances between them.

Solids have definite shape and volume, liquids have definite volume and assume the shape of the container, gases expand to fill and take volume and shape of the container.

The particles in all three states move about. The animation illustrates this idea. The amount of movement is smallest in solids, greater in liquids, and very great in gases.

Solid

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Liquid

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Gas

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Physical properties are things that can be seen or measured by physical means such as solubility, volume, length, color, odor, melting point, mass, boiling point. The physical properties are measured or observed without changing the identity of the substance or matter in the object. The particles retain their identity, but they are rearranged into a different pattern or no pattern at all.