Environmental Studies · Geography

Atmospheric Structure and Ozone

1,319 Questions

Atmospheric structure and ozone layer topics examine the Earth's atmospheric layers, the impact of solar radiation, and ozone depletion mechanisms. These environmental science concepts are crucial for general awareness sections in multiple competitive examinations. Review these questions to solidify your understanding of the stratosphere, polar vortex effects, and greenhouse gases.

Earth's atmospheric layersOzone layer depletionSolar ultraviolet radiationPolar vortex effectsCarbon dioxide impactOzone-depleting substances

Atmospheric Structure and Ozone Questions

Multiple choice zoology allotropy of oxygen ozone - a case study stratospheric pollution ozone and its depletion

In the upper layers of atmosphere, ozone is formed ?

  1. By action of electric discharge on oxygen molecules

  2. By action of ultraviolet rays on oxygen molecules

  3. By action of infrared rays on oxygen molecules

  4. Due to sudden drop of pressure
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • In the upper layer of atmosphere, the Ultraviolet rays (UV rays) split the molecule of oxygen $(O _2)$ into its constituent 2 atoms.
  • Each of the atom then combine with another oxygen $(O _2)$ molecule which gives rise to Ozone$(O _3)$.
  • Hence option B is correct answer.
Multiple choice zoology allotropy of oxygen ozone - a case study stratospheric pollution ozone and its depletion

Assertion : Ozone is destroyed by CFCs in the upper stratosphere

Reason : Ozone holes increase the amount of UV radiation reaching the earth.

  1. Assertion and reason are correct , but the reasons is not the explanation for the assertion

  2. Assertion is false, but the reason is correct

  3. Assertion and reason are incorrect, Assertion and reason are both correct

  4. And the reason is the correct explanation for the assertion
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The upper stratosphere consists of ozone $(O _3)$, which protect us from harmful ultraviolet (UV) radiations coming from the sun.
When CFC reacts with ozone it breaks the molecule of ozone resulting in ozone layer depletion.
Multiple choice zoology allotropy of oxygen ozone - a case study stratospheric pollution ozone and its depletion

A considerable part of the harmful $UV$ rays of the sum does not reach the surface of the earth. This is because high above the earth's atmosphere, there is a layer of___________.

  1. $O _3$
  2. $CO _2$
  3. $SO _2$
  4. $NO$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is because of ozone layer.Ozone is a gas in the atmosphere that protects everything living on the Earth from harmful ultraviolet (UV) rays from the Sun.The ozone layer absorbs ultraviolet (UV) radiation from the sun, preventing most of it from reaching the earth's surface. 

Multiple choice zoology allotropy of oxygen ozone - a case study stratospheric pollution ozone and its depletion

The absorption of $UV$ radiation by $O _3$:

  1. protects the inhabitants of our planet from injurious radiation
  2. maintains an equilibrium between the concentrations of $O _2$ and $O _3$

  3. makes both the function A and B above effective

  4. makes no function effective
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

We know that, UV-B radiation is very harmful. 


The UV light will also destroy ozone and break ozone back down into atomic oxygen (O) and diatomic oxygen ($O _2$) Therefore, the ozone layer does a great job filtering UV radiation and this process protects the inhabitants of our planet from injuries radiation and adsorption of UV radiation has maintained the equilibrium between the con. of oxygen and ozone in the atmosphere.


So, A and B are both effective 

C is the correct answer.

Multiple choice zoology allotropy of oxygen ozone - a case study stratospheric pollution ozone and its depletion

Ozone layer is being depleted. This is due to :

  1. NO (Nitrogen oxide) emission from supersonic jets

  2. Chlorofluorocarbon used as aerosols

  3. Both (a) and (b)

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Chlorofluorocarbons (CFCs) and other halogenated ozone-depleting substances (ODS) are mainly responsible for ozone depletion.


Depletion of the ozone layer is likely to aggravate existing health effects caused by exposure to UV radiation, as stratospheric ozone is a particularly effective UV radiation absorber. As the ozone layer becomes thinner, the protective filter provided by the atmosphere is progressively reduced. 

Consequently, human beings and the environment are exposed to higher UV radiation levels, and especially higher UV levels that have the greatest impact on human health, animals, marine organisms and plant life.


Hence, option C is correct.

Multiple choice zoology allotropy of oxygen ozone - a case study stratospheric pollution ozone and its depletion

State True or False.
The main function of ozone is to absorb sun's UV radiations, hence protecting the Earth from its harmful effects.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
True.
The main function of ozone is to absorb Sun's UV radiations, hence protecting the Earth from its harmful effects. The function of the ozone layer is to shield the earth from the harmful ultraviolet rays of the sun and to keep the Earth warm.
Multiple choice zoology allotropy of oxygen ozone - a case study stratospheric pollution ozone and its depletion

Which of the following chemicals is responsible for ozone layer destruction?

  1. Chlorofluorocarbons

  2. Halogens

  3. Hydrofluorocarbons

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
The chemicals responsible for ozone layer destruction are:

  • Chlorofluorocarbons: Chlorofluorocarbons (CFCs) are non-toxic, non-flammable chemicals containing atoms of carbon, chlorine, and fluorine. They are used in the manufacture of aerosol sprays, blowing agents for foams and packing materials, as solvents, and as refrigerants.

  • Halogens: Ozone is destroyed by reactions with chlorine, bromine, nitrogen, hydrogen, and oxygen gases. Reactions with these gases typically occur through catalytic processes. Because of catalytic reactions, an individual chlorine atom, on an average, can destroy nearly a thousand ozone molecules, before it is converted into a form harmless to ozone.

  • Hydrofluorocarbons: The HFCs are a class of replacements for CFCs and affect the ozone layer. 
Multiple choice zoology allotropy of oxygen ozone - a case study stratospheric pollution ozone and its depletion

The ozone layer is important because it:

  1. is used by living organisms for respiration.

  2. increases the temperature of the earth.

  3. reduces the amount of ultraviolet rays reaching the earth.

  4. reflects the heat from the earth back into the atmosphere.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The ozone layer is important because it absorbs ultraviolet (UV) radiation from the sun, preventing most of it from reaching the earth's surface. Radiation in the UV spectrum has wavelengths just shorter than those of visible light.

So answer is C.

Multiple choice zoology allotropy of oxygen ozone - a case study stratospheric pollution ozone and its depletion

The ozone layer in our atmosphere protects us from the bad effects of:

  1. Carbon dioxide

  2. CFC's

  3. The sun's ultraviolet rays

  4. All of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The ozone layer acts as a filter for the shorter wavelength and highly hazardous ultraviolet radiation (UVR) from the sun, protecting life on Earth from its potentially harmful effects. When the sky is clear, there is an inverse relationship between stratospheric ozone and solar UVR measured at the Earth’s surface. That is,the lower the ozone levels, the higher the solar UVR.


Hence, the correct option is $\text{C}$

Multiple choice zoology allotropy of oxygen ozone - a case study stratospheric pollution ozone and its depletion

Ultraviolet radiation from sunlight causes the reaction that produces:

  1. $SO _2$

  2. CO

  3. Ozone

  4. Fluorides
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Air pollution is formed through the reaction of solar radiation with airborne pollutants like nitrogen oxides and volatile organic compounds. These compounds, which are called primary pollutants, are often introduced into the atmosphere through automobile emissions and industrial processes. Ultraviolet light can split nitrogen dioxide into nitric oxide and monatomic oxygen; this monatomic oxygen can then react with oxygen gas to form ozone. 

Therefore, the correct answer is option C.

Multiple choice zoology allotropy of oxygen ozone - a case study stratospheric pollution ozone and its depletion

Ozone in stratosphere is depleted by :

  1. $CF _2Cl _2 $
  2. $C _7F _{16}$
  3. $C _6H _6Cl _6$
  4. $C _6F _6$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Ozone is depleted by $CF _2Cl _2$ (dichloro-difluoromethane or freon.)
The ozone layer is a region of Earth's stratosphere that absorbs most of the UV radiations.
Cholorofluorocarbons are mainly responsible for the depletion of this ozone layer.

Multiple choice zoology allotropy of oxygen ozone - a case study stratospheric pollution ozone and its depletion

In the stratosphere, what does screen out a large fraction of the ultraviolet rays of the sun?

  1. $H _2$
  2. $SO _2$
  3. $CO$
  4. $HCl$
  5. $O _3$
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

In the stratosphere, ozone $\displaystyle O _3 $ screen out a large fraction of the ultraviolet rays of the sun. Thus, ozone acts as a protective shield. Thus, due to presence of ozone layer, the harmful ultraviolet rays cannot penetrate earth's atmosphere. Hence, they cannot reach us.

Multiple choice zoology allotropy of oxygen ozone - a case study stratospheric pollution ozone and its depletion

Ozone deplete due to the formation of following compound in antartica?

  1. Acrolein

  2. peroxy acetyl nitrate
  3. $SO _2$ and $SO _3$

  4. Chlorine nitrate
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The ozone depletion was related to halogen (chlorine)-catalyzed chemical reaction which takes place in the spring season in the Antarctic polar region. The chlorine is derived from manmade chlorofluorocarbons and reacts with nitric acid forms chlorine nitrate($ClONO _2$) (CFCs) in the stratosphere.

Hence option D is correct.