The blog discusses the Questions and Answers from the chapter 20, All About Glass, English from Class 4. Students can use these answers for reference in their studies.
Q1. Find the following lists from the passage and copy them :
* Everyday things made of glass :
a) light bulbs
e) reading glasses
g) window panes
* What you can do with hot liquid glass
Ans. We can do the following things with hot liquid glass :
a) pour it
b) mould it
c) roll it
d) press it
e) blow it.
* Names of colours.
Ans. Following are the names of colors:
4. ruby red
8. deep yellow
11. dark green
Q2. Guess the meaning of the following words from the passage :
• molten – a state upto which a solid substance on heating flows like a liquid
• transparent – a substance that allows us to see through
• impermeable – a substance that does not allow a liquid or gas to pass through
• impart – to transfer or pass on to something
• recyclable – a thing that can be recycled, i.e. a thing that can be used again and again.
Q3. Write short notes on the following :
• How glass is made.
Ans. Glass is made by heating a mixture of clean white sand and chemicals like soda and lime. The mixture is heated in a furnace till it
turns into hot, liquid glass. When it cools down, it becomes stiff and hard.
• How glass is shaped.
Ans. Glass is brittle, hence it is shaped into different articles only when it is hot and soft. Very hot glass is more like a liquid and hence can be easily poured, moulded, rolled, pressed and blown to make a variety of shapes.
• Some properties of glass.
Ans. Glass has many useful properties as follows :
1. Glass is transparent, we can see through it.
2. It is strong and hard, we can put a lot of load on it.
3. It is impermeable, hence it does not allow water or other liquids to pass through it.
4. It has no effect on water or food material stored in it i.e. it does not smell or taste to them.
5. It has smooth surface and hence can be washed easily.
6. It looks beautiful.
• Coloured glass.
Ans. Ordinary glass is colourless, but it is possible to produce coloured and transparent glass by using different combinations of chemicals in the glass making process. Glass can be given many beautiful colours like –
4. ruby red
8. deep yellow
11. dark green, and even
12. black and white
Q4. Find out how paper and plastic are recycled.
Ans. Recycling of paper:
The process of paper recycling involves collection waste paper and then mixing it with water and chemicals to chemically break it down. First these papers are chopped and heated so that it gets converted to strands
of cellulose. This mixture is also called pulp or slurry. It is then filtered and to remove impurities, washed, de-inked, bleached and mixed with water. This can then be used to make new papers.
Recycling of plastics:
Before recycling the plastics are collected and sorted based on their colors and type. They are shredded and washed to eliminate any impurities. The material is melted and extruded into amall pellets. These small pellets are then used to make other plastic materials.