3.3: Solids dissolve more easily in hot water than in cold water (a…

Earth and Sky at Home Grades K–5

Make a rainbow on the kitchen floor, grow crystals on a windowsill and build a cloud in a jar. Three classic home experiments that actually work, with the real science explained for grown-ups.

• Where do rainbows come from? 45 min, plus 10 min outside on a sunny day

  Children split sunlight into colours with a glass of water, test whether the water is what makes the rainbow, and make their own rainbow with a hose mist. They finish able to explain that white light is a mix of colours that water bends apart.

• How do crystals grow? 40 min to set up, then 5 min a day for 5 to 7 days

  Children watch the grown-up make strong salt, Epsom salt and sugar solutions, set out dishes and a string, then check them every day for a week. They finish able to explain that crystals form when dissolved particles line up as the water leaves.

• How does a cloud form? 40 min

  Children watch the grown-up set up two jars of hot water with ice on top, add a wisp of smoke to one, and compare the clouds. They finish able to explain that clouds form when moist air cools and water collects on tiny specks.

Kitchen Chemistry for Families Grades K–5

Four famous kitchen experiments, done properly: a homemade lava lamp, oobleck, a baking soda volcano and invisible ink. Each one starts with a real question, works with things from your cupboard, and leaves your child able to explain what happened.

• Why do the blobs in a lava lamp go up and down? 45 min

  Kids layer oil and water in a glass, add food colouring and a piece of fizzy tablet, and watch coloured blobs rise and sink. Then they explain it with floating, sinking and gas bubbles, and test whether warm water changes the show.

• Is oobleck a solid or a liquid? 45 min

  Kids mix cornstarch and water into oobleck, then poke, squeeze, slap and drip it to find out when it acts like a solid and when it acts like a liquid. They finish able to explain why speed and force change the way it behaves.

• What makes a volcano erupt? 45 min

  Kids test baking soda and vinegar to find out where the fizz comes from, build the classic kitchen volcano, then open bottles of sparkling water to see what really drives an eruption: gas trapped under pressure. They finish able to explain how the model is like a real volcano, and how it isn't.

• How do spies write secret messages? 45–60 min

  Kids write invisible messages in baking soda, then reveal them by painting on grape juice or turmeric water, which change colour where the baking soda is. They finish able to explain that acids and bases make some colours change, and why a plain-water message stays hidden.

Winter Science at Home Grades K–5

Make frost on the outside of a can, race ice cubes with salt and sugar, lift an ice cube with a piece of string, and look inside a real snowflake. Three kitchen-table winter experiments that actually work, with the real science explained for grown-ups.

• Can you make frost in a can? 40 min

  Children crush ice, pack it into two cans, add salt to one, and watch water and then frost appear on the outside. They finish able to explain that the water and frost came out of the air, not through the can.

• Why does salt melt ice? 40 min

  Children race three ice cubes covered in salt, sugar and nothing, then use a pinch of salt to lift an ice cube out of a glass with a piece of string. They finish able to explain that salt melts ice by mixing into the water, and that it makes the ice colder, not warmer.

• What's inside a snowflake? 45 min on a snowy day, or 40 min plus overnight without snow

  Children catch falling snowflakes on a chilled dark cloth and look at them with a magnifier, or, with no snow, look at freezer frost and grow crystals on a pipe-cleaner snowflake overnight. They finish able to explain that a snowflake is an ice crystal grown from water vapour, and why it has six sides.

Printable practice for 3.3

These pages practise a closely related idea; the match to 3.3 is partial.

• Kitchen Chemistry for Families workbook included with the unit

  2 practice pages, 2 readings, 1 word wall, 1 English-support page, 1 unit review, 1 unit test, with answer keys.

• Clean Water Challenge: Mixtures, Dissolving and Separating workbook included with the unit

  3 practice pages, 3 readings, 1 word wall, 1 English-support page, 1 unit review, 1 unit test, with answer keys.

• Solids, Liquids and Gases workbook included with the unit

  1 word wall, 1 practice page, 1 reading, 1 unit review, 1 unit test, with answer keys.

• Grade 4 Rocks and Minerals printable pack, written for Ontario; the skill matches

  3 practice pages, 2 readings, 1 activity, 1 assessment, with answer keys. Free sample.

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