✦ Lesson 5
Properties of materials
We choose a material to make something because of its properties: what it is like. Each property has two opposite words.
💎 Hardness
hard
difficult to scratch: diamond, the hardest natural material
soft
easy to scratch: talc
🪢 Flexibility
flexible
easy to bend: rubber
rigid
difficult to bend: wood
🛡️ Resistance
resistant
difficult to break: plastic
fragile
easy to break: glass
⚡ Conduction
conductor
heat or electricity travel through it easily: aluminium
insulator
heat or electricity don't travel through it easily: wood
🎯 Elasticity
elastic
stretches and goes back to its shape: rubber
inelastic
does not stretch: metal
🧂 Solubility
soluble
dissolves in a liquid: salt in water
insoluble
does not dissolve: rocks
🍳 Why is a pan made of metal and wood?
The metal is a good thermal conductor, so the heat reaches the food. The handle is wood or plastic, which are insulators, so you don't burn your hand!
💎 hard/soft · 🪢 flexible/rigid · 🛡️ resistant/fragile⚡ conductor/insulator · 🎯 elastic · 🧂 soluble