Lesson plan

States of Matter and State Changes

Define solid, liquid and gas. Use water to show state changes. End with a snack made through state changes.
Science content
Chemistry: States of Matter, Properties of Materials (K-7)
Chemistry: Physical Changes, Solutions, Mixtures and Separating (2, 4, 5, 6)

Do a selection of the activities. Suggested trio: epsom salt painting, acting out molecules, popcorn with skits.
If including the frost activity, set up frost cans in the centre of each table group at the start of the lesson. (They will be used as part of the state changes in water activity.)

At some point in the lesson introduce or review the concept of solid, liquid and gas:
Solids: fixed size and shape
Liquids: change shape to fit their container but has a fixed size so takes up the same amount of space as it flows
Gases: change shape and size to fill their container
Either ask students to point to examples the classroom, or do the states of matter scavenger hunt.
[Some students may also point out that plasma is also a state of matter, which it is. The sun contains plasma.]
Optional: book on states of matter: “Matter” First Fact book (Capstone Press)

Introduce that everything is made up of tiny tiny particles, too small to see. (An atom is 10-10m, or 10 million in a dot a mm wide.)
In a solid the particles are packed close together, that is why a solid feels hard. In a liquid they are further apart. In a gas they are far enough apart that we can move through them easily - move your hand through the air and the wind you feel on your hand is the molecules bumping into your hand.
Useful videos to show the particles in the different states:
Image of particles: http://wps.prenhall.com/wps/media/objects/943/966267/fig10.gif
1 minute video of the particles in solids, liquids, gases: https://www.youtube.com/watch?v=s-KvoVzukHo
Longer cartoon video of the particles in solids, liquids, gases at https://www.youtube.com/watch?v=guoU_cuR8EE

Act out the states of matter to model what the particles are doing in each case.

Look at state changes in water (including the icy frost formed on the cans, if they were set up).
Optional: as part of this activity measure the temperature of water in the different states of matter.

End with a snack that exploits state changes:
Popcorn and skits, or ice cream.


Laurier: states of matter in water, acting out molecules, popcorn.
Shaughnessy 1/2s and Douglas 2/3s: epsom salt painting, acting out molecules, popcorn

Grades taught
Gr 1
Gr 2
Gr 3
Gr 4
Gr 5
Teaching Site
Brock Elementary
Gordon Elementary
Laurier Elementary
Shaughnessy Elementary