Unit 6 : Material
TIPS
- Different objects are made of different materials. Examples:
- Clay – brick, porcelain vase, ceramic sink
- Rubber – ball, tyre, rubber gloves
- Silk – necktie, dress, scarf
- Glass – bottle, mirror, window pane
- Different materials have different properties. Examples:
- Cotton and paper can absorb water
- Rubber can be stretched
- Wood and most plastics float on water
- Clay, metal, paper and rubber sink in water
- Metal can conduct electricity and heat
- Plastics, rubber and wood does not conduct electricity and heat
- An object that allows all light to pass through it is said to be transparent.
- An object that allows some light to pass through it is said to be translucent
- An opaque object does not allow any light to pass through it.
COMMON MISTAKES
The figure below shows two groups of objects.
R
Manila Card
Q
Tracing Paper
Which of the following is correctly grouped?
| Q | R |
| A | Clear glass | Wooden ruler |
| B | Plastic bottle | Wok |
| C | Wooden ruler | Wok |
| D | Clear glass | Plastic bottle |
Χ Tracing paper is transparent.
√ Tracing paper is translucent and most of the plastic bottles is also translucent. While manila card is an opaque object.
So, the correct answer is B.
