7) RUSTING

What MATERIALS that can caused rusting?

• Wood

• Iron

• Plastic

• Metal

What are the CHARACTERISTICS of rusty objects?

• Reddish-brown colour, rough surface, brittle

• Black colour, smooth surface, wet

• White colour, smooth surface, dry

• Blue colour, rough surface, brittle

What are the factors that cause rusting?

• The presence of water and air
• The presence of air.

• The presence of water.

• Nothing

What are the ways to prevent rusting?

• Apply water

• Just ignore

• Coating

• Painting

The importance of preventing rusting are:

• - Safe to be used.

• - Look pleasant.

• - Save on maintanance cost.

• - Durable and not easily damaged.

• False

• I dont know

• True

• Maybe

Which material cannot rust?

• Iron

• Plastic

• I dont know

• We dont learn this yet!

Why plastic cannot rust?

• Because it made of wood

• Because it made of concrete

• Because it made of iron

• Because it made of plastic

Sally's house gate has rusted. What should he do?

• Destroy it.

• Paint it.

• Leave it.

• Ignore.

If Sally didnt paint his gate, what can caused?

• The gate will broke.

• The gate stay safe.

• The gate look pleasant.

• The gate smells.

Now, if you have bicycle: if the chain has rusted, what should you do?

• Apply water

• Apply oil or grease

• Apply hot water

• Apply painting