YEAR 4 SCIENCE CHAP 8

What is the basic source for leather, wool and silk?

• Plants

• Animals

• Vegetables

• Petroleum

Door is made of wood as it is easy to shape, strong, last long and good sound insulation

• True
• False

Answer explanation

Wood is easy to shape, provides security as it is not easy to break, strong, and good sound insulation

Which of the following below are correct way to choose a material?

• Need to know about the disadvantages only

• Choose costly materials to last long

• Knows the advantages and disadvantages of the materials

• Choose fragile materials to cut cost

Glass is used to invent kitchen utensils as they are chemical resistance and heat resistance

• True
• False

Answer explanation

Glass is chemical resistance, helps to not absorb/release any chemicals from/into foods. Glass is also a good heat resistance. So, it withstands high temperature.

Which of the materials used to invent a car?

• Wood, plastic, glass

• Glass, leather, metal, rubber

• Synthetic cloth, metal, wood

• Cotton, rubber, glass, copper

Answer explanation

To make a car, glass is used as mirrors, leather is used for the seats, metal is used to build the car structure/body and rubber is used to make the tyres.

We need to invent an item according to the available materials at market, not the properties of the materials and its function to support the item

• True
• False

Answer explanation

To invent an item, we need to see which materials are suitable and functions to support the item

What are the materials are made from plant sources

• Cotton, silk, wool

• Rubber, wood, cotton

• Synthetic cloth, sand, wood

• Clay, copper, cotton

Answer explanation

Plant sources are rubber (rubber tree), cotton (cotton plants) and wood (trees)

What are the materials can be used to make a jacket?

• Wool

• Plastic

• Cotton

• Rubber

Answer explanation

We can use boiled wool and cotton fibers to make a jacket

Which of the objects below floats on water?

• Wood

• Apple

• Cork

• Iron block

Answer explanation

Wood, apple and cork floats on water as they have lower density than water.

Is it true that plastic is a good electricity and heat insulator?

• True
• False

Answer explanation

Plastic do not let electricity and heat pass through it. They are widely use as insulators.