Grade Levels: K-3

This page provides information to support educators and families in teaching K-3 students about changing states of matter. It is designed to complement the Changing States of Matter topic page on BrainPOP Jr.

Remind your children that everything is made of matter. Matter is anything that takes up space and it is made up of tiny particles. Matter can come in different states, or forms, such as solids, liquids, and gases. Different types of energy, including heat, can change matter. Matter can change states through freezing, melting, evaporation, and condensation. We recommend reviewing the different kinds of matter by screening our Solids, Liquids, and Gases movie.

Review with your children that there are several different states, or forms, of matter. Solids have a definite shape and volume. The particles that make up a solid are closely packed together and do not have much space to move. Thus, solids keep their shape. Liquids flow and do not have a definite shape. Liquids take the shape of their containers. Pour a cup of water in different containers and have children observe how the shape changes. The particles that make up a liquid are farther apart than solids, and they can move around more readily. This allows liquids to flow and spread out. Gases also flow and do not have a definite shape. The particles that make up gases are farther apart than liquids, so gases can spread out in all directions to take the whole space of a container.

Different kinds of energy can cause matter to change states. Most children have experience with ice cream melting on a hot day or ice cubes melting in a glass. When a substance melts, it goes from a solid to a liquid. Heat causes the temperature of the substance to increase and particles to gain more energy. They are able to move faster and flow, causing a solid to change into a liquid.

Many children have poured liquid water into an ice cube tray and put it in the freezer to make ice, which is a solid. When a substance freezes, it loses heat and energy. Particles slow down and become more packed together. This causes liquids to change into solids. The freezing point of water is 32 degrees Fahrenheit. Different substances have different freezing points.

Adding heat to a substance can cause matter to change states. When a tea kettle full of liquid water is put on a stove, the temperature begins to rise. Particles gain more energy and are able to move and spread out more. When water boils, the liquid turns to a gas. This process is called evaporation. Your children may have observed that wet clothes will dry out if they are hung in a warm, sunny spot. The water in the clothes evaporates into the air.

Liquids can change into gases, but gases can also change into liquids. Many children have noticed droplets of water that collect on the side of a cup or glass. Water vapor is a gas in the air and when it comes in contact with the cool glass, the temperature decreases. The particles lose energy, turning the gas into a liquid. This process is called condensation.

Matter is all around us, in many different forms, and it can change. Encourage your children to observe their surroundings and ask questions. Have them make predictions and draw connections to prior knowledge to help them understand the world around them.