Final answer:
The three main states of matter are solid, liquid, and gas. Solids have a fixed shape and volume, liquids have a fixed volume but can change shape, and gases have neither a defined shape nor volume. Matter can change between these states through heating or cooling without changing its chemical composition.
Step-by-step explanation:
The three main states of matter are solid, liquid, and gas. These are the most common physical forms that matter can take under normal conditions. Each state has its distinctive properties. Solids have a fixed shape and volume. Examples of solids are ice sculptures or rocks. Liquids have a defined volume but take the shape of the container they are in, like a beverage in a soda can. Gases do not have a definite shape or volume and will expand to fill whatever container they are in, such as air in a tire or the clouds in the sky. Matter can transition between these states through the addition or removal of heat, which is referred to as a change of state.
When we heat a solid, it can become a liquid, and further heating can turn it into a gas. Conversely, cooling a gas can condense it into a liquid, and further cooling can solidify it into a solid. These changes do not alter the chemical composition of the substance, only its physical form.