Lesson 2: Sieving

Hand out the children's exercise books. Ask the children to use a ruler to split a page into four parts and write one of the following headings in each section: solid-solid, solid-liquid, liquid-gas and gas-gas. Make a class version on flipchart paper that the children can refer to and add throughout the unit.

Read the list of mixtures below and ask the children to sort each mixture into the correct section of their table.

• Seawater.

• Sand.

• Soil.

• Fizzy drink.

• Gunpowder.

• Air.

• Water and pebbles.

• Coffee.

• Greenhouse gases.

• Salt.

Mark the answers as a class and add to the class flipchart:

• Solid-solid: sand, soil, gunpowder and coffee.
• Solid-liquid: seawater, water and pebbles.
• Liquid-gas: fizzy drink.
• Gas-gas: air and greenhouse gases.

Explain that the children learnt in the last lesson that salt is not a mixture so it does not belong in any of these sections.