The 3 states of matter: solids, liquids and gases
Substances can also be classified as solids, liquids or gases.
The particles in a solid, liquid and gas are arranged differently:
Changes of state can happen if a substance is heated or cooled.
Some substances can change directly from solid to gas without becoming a liquid in between. This is called When a solid turns straight into a gas on heating, without becoming a liquid first - or when a gas turns straight into a solid, without becoming a liquid.. Under normal conditions, solid carbon dioxide ('dry ice') can Able to change from a solid to a gas, or from a gas to a solid, without becoming a liquid..