Even when liquids change their shape, they always take up the same amount of space. Their volume stays the same. Examples of gases include steam, helium and oxygen. They are often invisible.

Although the three states of matter are solid, liquid, and gas, not all substances seem to fit perfectly into one of these groups. Take a look at the substance below and see if you can decide whether ...

After viewing a model of salt, students help develop models for the processes of salt dissolving, water evaporating to form a gas, and salt re-forming as a crystal. The focus is that matter, whether ...

Cryogenic liquids are materials with a boiling point of less than – 100 °F (-73 °C); common examples include liquid nitrogen, helium, and argon, and dry ice/alcohol slurries. Cryogenic liquids undergo ...

Gases, on the other hand ... they gain energy and can move more freely, changing from a solid to a liquid, for example. This basic model is, however, just that: there are many, many more states ...

In gases the particles are far apart ... so would feel very heavy. Some liquids have a higher density than solids. For example, wood is a solid but has a lower density than water, which is ...