A mixture is two or more materials jumbled together — and what has been mixed can usually be un-mixed. At Mixing Marsh, Year 4 scientists learn which materials dissolve, and how to choose the right way to separate a mixture.
Apa yang akan dipelajari anak anda
- Know that a mixture can be separated because its parts are not joined
- Sort materials into soluble (dissolves) and insoluble (does not dissolve)
- Separate mixtures by sieving, filtering, using a magnet and evaporating
- Choose a method by thinking about how the parts are different
Use the difference
Every separating method relies on a difference. A sieve uses size: small grains fall through, big ones don’t. A magnet uses magnetism: it lifts out iron. A filter holds back solid bits while liquid passes through.
Dissolved, not gone
When salt dissolves in water it breaks into pieces too small to see, making a solution. It hasn’t disappeared — you can taste it. A filter can’t catch it, but if the water evaporates, the salt is left behind as crystals.
Contoh soalan
Berikut ialah beberapa soalan seperti dalam misi pertama. Bolehkah anda menjawabnya?
1. What could you use to pull iron nails out of sawdust?
🧲- A magnet
- A sieve
- A fan
- A spoon
Tunjuk jawapan
Jawapan: A magnet. Iron is attracted to a magnet; sawdust is not.
2. True or false? A fruit salad is a mixture.
Tunjuk jawapan
Jawapan: Betul. The pieces of fruit are mixed, and you could pick them apart again.
3. Muddy water is poured through paper in a funnel. What is this called?
- Freezing
- Melting
- Filtering
- Dissolving
Tunjuk jawapan
Jawapan: Filtering. The filter paper traps the mud and lets the water through.
Tip untuk orang dewasa
- Mix sand, salt and paper clips, then work out together how to get each one back.
- Leave a saucer of salty water on a sunny windowsill and watch the crystals appear.
- Use a tea strainer or coffee filter and talk about what gets through.