DK - WOW! The Visual Encyclopedia of Everything

Everything you can smell, touch, or taste is made from matter, including living things such as yourself, and non-living things such as this book. Matter is made up of atoms and anything that is not made of matter is energy. Heat, light, and sound are forms of energy. You cannot smell, touch, or taste energy, and it is not made from atoms. All matter on Earth exists in one of three states: solid, liquid, or gas.

States of matter

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STATE TO STATE

Matter changes from one state to another when it is heated or cooled. Heating melts solids into liquids and boils liquids to form gases. Cooling condenses gases to form liquids and freezes liquids into solids. As matter changes from one state to another, the atoms within it remain the same but become arranged differently.

Unlike most substances, water expands when it freezes (rather than contracting) because its molecules move further apart when locked into the rigid structure of a solid

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CHANGING SHAPE

Solids do not always have a fixed shape. Some solids, such as ice or glass, are brittle and will break if you hammer or crush them. Other solids, such as rubber or metals, are malleable and can be hammered, stretched, or squashed into different shapes without breaking.

Most gases are invisible.

Even steam cannot be seen until it condenses

into a mist of droplets as

it mixes with cooler air

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SOLID

A solid, such as this ice sculpture, has a fixed volume and a shape that is not easy to change. Strong links hold atoms together and do not allow them to move around, as they can in a liquid and in a gas. The atoms in most solids are arranged

in regular patterns that form three-dimensional shapes, such as cubes and prisms, called crystals.^2

GAS

A gas does not have a fixed shape or a fixed volume. It expands to fill all the space around it. Atoms in a gas can move freely in every direction. They whizz around far too fast to ever stick together.

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