Solids, Liquids and Gases
Background Information & Activities

Matter is all around us. It makes up all things. Scientists classify matter into three main states: solids, liquids, and gases. There are other states, like plasma, but they are mostly beyond the scope of K-3 education. Under certain conditions, matter can change between different states. Please note that changing states of matter is covered in a separate movie.

A solid is a kind of matter that has its own shape and does not flow at a given temperature. The molecules that make up a solid are close together and have confined movement. Solids include tables, shirts, glass cups, and clay. A property is a trait or characteristic of matter. Solids can be different colors and textures and have different degrees of malleability. It is important for young children to be able to articulate the properties of an object, as well as classify objects by their properties. Mass is the amount of matter in an object. Students may believe that mass is the same as weight, but this is incorrect. Weight is based on the gravity’s pull on an object. Thus, the weight of an object on Earth is different from weight of the same object on the moon. Mass, however, does not change and is independent of gravity.

A liquid is a kind of matter that does not have its own shape and flows at a given temperature. Liquids take the shape of their containers. The molecules that make up a liquid are farther apart than solids and are able to vibrate and move more freely. Liquids include water, blood, milk, and juice. Liquids can vary in color and viscosity, or thickness.

Like a liquid, a gas flows and does not have its own shape at a given temperature. Gases can take the shape of their containers. The molecules that make up a gas are much farther apart than solids and liquids, and can move independently. Without a container, gases can spread freely. Though you cannot always see gases, they surround us. Air is a mixture of different gases. The sun is also made up of gases. Volume is the amount of space matter takes up. Tools such as measuring cups and spoons can measure liquid volumes. The volume of a gas can be measured using specific formulas. The Sun is made of different gases and plasma. Plasma is an ionized gas, or a gas that is sensitive to magnetism.

Encourage your children to explore their surroundings and find examples of solids, liquids, and gases. How are they alike? How are they different? How do they use solids, liquids, and gases everyday?

Solids, Liquids and Gases Teacher Activities – Click Here!

Solids, Liquids and Gases Family Activities – Click Here!

Solids, Liquids and Gases Teacher Activities

Shapes Matter

Remind your students that liquids take the shape of their containers. Experiment pouring liquids into containers of different shapes and sizes. Then have students pour the same amount of liquid into each container. How do the shapes change? Why do some containers appear to have more liquid than others?

As an extension, help students blow air into balloons to make different shapes. Balloons can be small, large, tube-shaped etc. Encourage students to make balloon animals to show how gas can be moved and contained. Compare how liquids and gases fill their containers.

Mass Mania

Review with your students that mass is the amount of matter in an object. Explain that some objects may seem very large but have little mass. For example, a balloon is bigger than a key, but the balloon has less mass. A foot of yarn is longer than a marble, but the marble has more mass. Brainstorm different examples. If possible, have small groups use balance scales and gram measurements to compare the masses of different objects.

Property Game

Discuss different properties of objects, such as color, texture, smell, etc. Then have students choose objects and write riddles that describe their properties. Encourage your students to write riddles for solids, liquids, and gases. Have students read their riddles and invite volunteers to guess the object. For example, a student might say: “What is solid, wooden, tall and attached to our wall?” Encourage students to think about how the objects are alike and different from each other.

Solids, Liquids and Gases Family Activities

State House

Walk with your child around your home and find objects that are solids, liquids, and gases. Solids can include furniture and clothing, liquids can include condiments and juices in your refrigerator, and gases can include aerosol cans such as hair sprays and air fresheners. Encourage your child to describe the properties of each kind of matter and write down his or her observations in a notebook.

Liquid Lunch

Together examine the properties of different liquids in your home and compare and contrast them. You can investigate liquids such as water, heavy cream, juice, glue, rubber cement, etc. Which liquids are thick? Which are thin? Which spread quickly on a surface? Which are clear? Which liquids are harmful (toxic) and which are healthy? Which things look solid, but can be turned into liquids? Encourage your child to write his or her observations and ideas in a Venn diagram, compare-and-contrast chart, or other graphic organizer.