6th Grade > Chemistry
AIR AROUND US MCQs
Total Questions : 100
| Page 8 of 10 pages
Answer: Option D. ->
Ozone
:
D
Ozone is a colourless gas that can be found throughout all layers of our atmosphere. Most ozone is found in the stratosphere, which begins at about 10–16 kilometres above earth’s surface. The ozone layer protects us by absorbing potentially harmful ultraviolet (UV) radiation from the sun. The UV rays can cause sunburn and skin cancer.
:
D
Ozone is a colourless gas that can be found throughout all layers of our atmosphere. Most ozone is found in the stratosphere, which begins at about 10–16 kilometres above earth’s surface. The ozone layer protects us by absorbing potentially harmful ultraviolet (UV) radiation from the sun. The UV rays can cause sunburn and skin cancer.
Answer: Option A. ->
cut off the oxygen supply.
:
A
In order for a fire to burn, all three elements must be present: heat, fuel and oxygen. If any of the elements are cut off the fire will be put out.
As blanket completely surrounds the person, it seals the person’s body surface around the fire and cuts off the oxygen supply to the fire, thereby putting it out. Hence, blanket acts as a fire extinguisher and stops the fire from spreading.
:
A
In order for a fire to burn, all three elements must be present: heat, fuel and oxygen. If any of the elements are cut off the fire will be put out.
As blanket completely surrounds the person, it seals the person’s body surface around the fire and cuts off the oxygen supply to the fire, thereby putting it out. Hence, blanket acts as a fire extinguisher and stops the fire from spreading.
Answer: Option A. ->
Oxygen
:
A
Oxygen is the colourless, odourless gas which supports combustion. Rest of the gases given here don't support combustion.
:
A
Oxygen is the colourless, odourless gas which supports combustion. Rest of the gases given here don't support combustion.
Answer: Option A. ->
Air is a mixture of many gases.
:
A
Air occupies space and has mass, therefore, it is matter. Air can be compressed and it exerts pressure in all the directions. For example, when we inflate a balloon, air occupies the space in the balloon and exerts pressure on the walls of the balloon. Air around us is a mixture of gases. It contains nitrogen, oxygen, argon, other gases and also water vapour.
:
A
Air occupies space and has mass, therefore, it is matter. Air can be compressed and it exerts pressure in all the directions. For example, when we inflate a balloon, air occupies the space in the balloon and exerts pressure on the walls of the balloon. Air around us is a mixture of gases. It contains nitrogen, oxygen, argon, other gases and also water vapour.
Answer: Option A. ->
True
:
A
Carbon dioxide fire extinguishers are being used extensively. When sprayed, it forms a layer on the fire thereby cutting off the supply of oxygen. Carbon dioxide also spreads very fast and helps in the cooling of the combustible substance. By reducing the heat and cutting off oxygen supply it extinguishes the fire.
:
A
Carbon dioxide fire extinguishers are being used extensively. When sprayed, it forms a layer on the fire thereby cutting off the supply of oxygen. Carbon dioxide also spreads very fast and helps in the cooling of the combustible substance. By reducing the heat and cutting off oxygen supply it extinguishes the fire.
Answer: Option C. ->
Statement I is true and statement II is true.
:
C
The burning of fuel releases harmful gases in the atmosphere. The tall chimneys in factories would take away the gases from the breathing level of the living organisms and would release them high into the atmosphere.
:
C
The burning of fuel releases harmful gases in the atmosphere. The tall chimneys in factories would take away the gases from the breathing level of the living organisms and would release them high into the atmosphere.
Answer: Option D. ->
The flame was put off and water rose in the jar.
:
D
The flame of the candle will burn till there is oxygen available in the jar. After sometime, when all the oxygen is consumed, candle flame will go off. The water from the container will rise in the jar to occupy the space of the consumed oxygen gas.
:
D
The flame of the candle will burn till there is oxygen available in the jar. After sometime, when all the oxygen is consumed, candle flame will go off. The water from the container will rise in the jar to occupy the space of the consumed oxygen gas.
Answer: Option D. ->
Wind
:
D
:
D
Moving air is known as wind. Short bursts of wind moving at high speeds are known as gusts. Depending on their strength, winds can be known as a breeze, gale, storm or hurricane.
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