Unit 3: Changing materials

Squash, bend, twist and stretch materials; heat and cool them; and find out why the sea is salty.

• 3.1 Changing shape – Squash it, roll it, shape it!
• 3.2 Bending and twisting – Bend a straw, twist a towel.
• 3.3 Fantastic elastic – Stretchy things that spring back.
• 3.4 Heating and cooling – Melt it, freeze it, cook it!
• 3.5 Why is the sea salty? – Where does the salt come from – and how do we get it out?