Solids, Liquids, and Gases at Home

All the materials around you can be described as solids, liquids, or gases.

Melting Points

Different materials melt at different temperatures. The chart shows the melting points of some materials you know. You might find some of these materials in your kitchen.

Chocolate melts at about 97°F (36°C), which is just below body temperature. Chocolate feels good to eat because it melts in your mouth!

The temperature in a room is usually around 65°F (18°C). A material with a melting point lower than this will be a liquid. Olive oil and water are liquids at room temperature.

Boiling Points

Different materials also boil at different temperatures. Liquids such as milk and fruit juice are mostly water. This means they should boil at about the same temperature as water does. So they boil at around 212°F (100°C).

Is Sugar a Solid or a Liquid?

Solids have fixed shapes. Liquids flow and take the shape of the container you put them into. The surface of a liquid is flat. Sugar has some of the properties of a liquid. You can pour it from one container into another. It will take the shape of the container you put it in.

Sugar has some of the properties of a liquid. It also has some of the properties of a solid.

Sugar also has some of the properties of a solid. You can make a pile of sugar. But it does not end up with a flat surface unless you smooth it out.

Look closely at the sugar. You can see that it is made of tiny crystals. The crystals are solid. Solid materials sometimes act like liquids if the pieces are very small. Other solid materials that can act like liquids are salt and sand.

Mixtures of States

Many things around you are combinations of materials in different states.

Some hairspray comes in a spray can. Hairspray is a mixture of tiny drops of liquid and a gas. The liquid is a chemical that keeps your hair in place. The gas helps spray the drops of liquid over your hair. A mixture with drops of liquid in a gas is called an aerosol.

Foam rubber is solid rubber with lots of air bubbles in it. Foam rubber is soft and squashy. It is used for cushions and toys.

A foam (cream) on top of an emulsion (milk).

Some foods are also mixtures. Milk is a mixture of water and droplets of liquid fat. Mixtures of two liquids are called emulsions. Whipped cream is a foam of air bubbles in a liquid.