YEAR 5 SCIENCE CHAP 7

What is rusting process?

• A process where oxygen is used to produce energy

• A process where the rust is formed by the presence of carbon dioxide

• A process where the rust is formed on iron due to the presence of oxygen and water

• A process where the rust is formed on iron due to the presence of water

Adding carbon dioxide into the tube of nail (with water) can prevent rusting.

• True
• False

Answer explanation

Carbon dioxide can eliminate the presence of the oxygen. However, the nail does not rust only with the presence of water. Both water and oxygen are needed in rusting process.

Choose the objects that rusts

• Silk, Rubber, Leather

• Wood, Iron, Steel

• Iron, Glass, Diamonds

• Iron, Steel

Choose the objects that do not rusts

• Iron, Rubber, Clay

• Glass, Plastic, Wood

• Iron, Paper, Silk

• Plastic, Steel, Cotton

Paint can increase the rusting process

• True
• False

Answer explanation

Paint avoids the direct contact of iron with oxygen and water.

Adding oil on the hinges prevents rusting process and make the hinges work for a long time

• True
• False

Sally owns an old car. The car's body parts started to rust, and the door hinges makes squeaky noises when it is opened and closed. What should Sally do to prevent further rusting?

• Place the car inside a dark room

• Paint the car's body parts

• Coat the hinges with oil/grease

• Add water to the hinges

Answer explanation

Paint can avoid the metal to direct contact with oxygen and water while adding oil/grease on the hinges helps to avoid the contact of oxygen and water.

We can use non-rusty materials to coat the metals so that the rusting process will not occur

• True
• False

Choose the importance to prevent rusting.

• To replace with new objects

• To save cost of production

• To reduce the quality of the product

• To have a long durability

How can you fasten the rusting process of a nail?

• Add cooking oil

• Use moisture absorber

• Place inside tap water

• Put inside a container filled with nitrogen

Answer explanation

Tap water consist of both water and oxygen that helps the rusting process