Matter on the Move: Heat, Mixtures and Change

You need: 3 plastic syringes (no needles) with caps or fingers over the tip · water · dry sand · particle diagram sheet

1. Fill one syringe with air, one with water and one with sand. Block the tip with a cap or your finger.
2. Push each plunger gently. Measure how far it moves using the scale on the side.
3. Record the distances in a table.
4. Draw what the particles might look like inside each syringe before and after pushing.

How you'll know: Your drawings show gas particles with lots of empty space between them, which is why the air squashed most.

Safety: Syringes without needles only. Point them at the sink, not at people.

Go further: Warm the air syringe in your hands for a minute with the tip blocked. Does the plunger move? Explain why using particle movement.

You need: ice cubes the same size · a metal tray or baking tin · a plastic lid · a wooden chopping board · a stopwatch

1. Leave all three surfaces in the room for an hour so they are the same temperature.
2. Put one ice cube on each at exactly the same time.
3. Time how long until each cube is fully melted, or measure the puddle after 5 minutes.
4. Repeat with fresh cubes and work out the average.

How you'll know: The ice on metal melts first because metal is a good conductor: it passes heat from the room into the ice quickly.

Go further: Explain why the metal tray felt colder to your hand even though it was the same temperature as the wood.

You need: a large clear container of cold water · a small jar · warm tap water · food colouring · tongs or string to lower the jar

1. Fill the small jar with warm water and add two drops of food colouring.
2. Carefully lower the small jar, open side up, to the bottom of the big container of cold water.
3. Watch for two minutes without bumping the table. Draw what the colour does.
4. Repeat with cold dyed water in a room-temperature container and compare.

How you'll know: The warm coloured water rises in a plume and spreads at the top, showing a convection current: warm water is less dense and floats up.

Safety: Warm tap water only. Wipe spills straight away.

Go further: Explain how the same idea moves warm air around a room with a heater and why ceilings lose so much heat.

You need: 5 identical jars with lids · hot tap water · wool, bubble wrap, newspaper, foil (same thickness or number of layers) · rubber bands · thermometers · stopwatch · results table

1. Wrap four jars, each in a different material. Leave one unwrapped as your control.
2. Pour the same amount of hot tap water into every jar and put the lids on.
3. Measure the starting temperature of each jar.
4. Measure again every 5 minutes for 30 minutes.
5. Work out each jar's total temperature drop and draw a line graph.

How you'll know: The best insulator has the smallest temperature drop compared with the control, and the pattern shows up again when other groups repeat the test.

Safety: Hot tap water only, poured by an adult. Hold jars by the lid, not the sides, if they are hot.

Go further: Test whether two thin layers beat one thick layer of the same material. What does trapped air have to do with it?

You need: 3 identical cans or jars · black paper, white paper, aluminium foil · water · thermometers · a sunny window or a desk lamp

1. Wrap one can in black paper, one in white and one in foil.
2. Fill each with the same amount of room-temperature water.
3. Place them side by side in the sun, the same distance from the window.
4. Take temperatures every 5 minutes for 20 minutes.

How you'll know: The black can warms fastest because dark surfaces absorb more radiation, while shiny foil reflects most of it.

Go further: Use your results to explain why chilly bins are often white, and why some solar hot water panels are black.

You need: a cup of mixed sand, salt, small paper clips and dried peas · a sieve · a magnet in a zip-lock bag · water · a funnel and filter paper or coffee filter · a saucer

1. Sieve out the peas.
2. Run the bagged magnet over the rest to lift out the paper clips.
3. Stir the sand and salt into water. The salt dissolves; the sand does not.
4. Filter the mixture. Sand stays in the paper; salty water drips through.
5. Leave the salty water on a saucer in a sunny place for a few days. Salt crystals appear as the water evaporates.

How you'll know: You end up with four separate piles, which proves the salt never disappeared: it was spread through the water as tiny particles.

Safety: Keep the magnet in a bag so filings or clips do not stick to it. Wash hands after handling the mixture.

Go further: Find out how Lake Grassmere saltworks uses the same idea on a giant scale, and what the sun and wind each do.

You need: sugar cubes or teaspoons of sugar · clear cups · cold, room-temperature and warm tap water · thermometer · stopwatch · spoons

1. Pour the same amount of water at three different temperatures into three cups. Measure each temperature.
2. Add one sugar cube to each at the same moment.
3. Stir each cup the same number of times every 10 seconds.
4. Time how long until you can see no more sugar.
5. Repeat twice and find the average.

How you'll know: Warm water dissolves the sugar fastest. Your particle drawing shows faster-moving water particles pulling the sugar apart quicker.

Safety: Warm tap water only. No tasting.

Go further: Do the opposite with gas: open a warm and a cold bottle of fizzy water. Which fizzes more, and what does it tell you about gas dissolving?

You need: goggles · baking soda and vinegar in a zip-lock bag · chocolate in a zip-lock bag · a bowl of warm water · damp steel wool in a jar (set up a week earlier) · a signs-of-change checklist

1. Melt chocolate in its bag in warm water, then let it set again. Record what happens.
2. Add a spoon of baking soda to a little vinegar in a bag and seal it. Feel the bag and watch.
3. Look at the steel wool that has been sitting damp for a week. Compare it with fresh steel wool.
4. Tick the signs of change for each: new colour, gas, temperature change, new solid.
5. Decide: physical change or chemical change? Reversible or not?

How you'll know: You can back up each decision with at least one observed sign, and you can say which ones could be turned back.

Safety: Goggles on. Do not seal the bag too tightly or let it burst near faces. Wear gloves for steel wool. Wash hands afterwards.

Go further: Watch or ask about a cooking process at home or in the marae kitchen (bread rising, a hāngī, a boiled egg) and decide which changes are chemical.