Q3
1 markVery Short AnswerSection A

What is the function of ozone at the higher level of atmosphere?

Our Environment
Ozone Layer and How it is Getting Depleted
Official Answer

At the higher levels of the atmosphere, ozone (O3O_3) performs an essential function by shielding the surface of the Earth from harmful ultraviolet (UV) radiation coming from the Sun. This radiation is highly damaging to living organisms and is known to cause skin cancer in human beings.

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Marking Scheme

  • 1Stating that it shields the Earth from ultraviolet (UV) radiation: [0.5 mark]
  • 2Mentioning that it protects organisms from damage / prevents skin cancer: [0.5 mark]

Hint

Think about the protective shield in the stratosphere that blocks harmful solar rays causing skin cancer.

Quick Oral Answer

Ozone shields the Earth from harmful ultraviolet (UV) radiation from the Sun, which can cause skin cancer and damage plants and animals.

Analysis & Explanation

Ozone is a deadly poison at ground level, but in the stratosphere (higher atmosphere), it is formed when high-energy UV radiation splits molecular oxygen (O2O_2) into free oxygen atoms (OO), which then combine with O2O_2 to form O3O_3. This layer acts as a protective shield absorbing harmful UV rays.

Common Mistakes

  1. 1Confusing ozone's role at ground level (where it is a pollutant/poison) with its protective role in the upper atmosphere.
  2. 2Stating that ozone blocks infrared radiation or greenhouse gases instead of UV radiation.

Interesting Facts

Although ozone is a deadly poison at ground level, life on Earth could not exist without the stratospheric ozone layer shielding us from lethal solar UV radiation.

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Frequently Asked Questions

How many marks does this question carry in CBSE Class 10 Science 2012?

This question carries 1 mark in the CBSE Class 10 Science 2012 examination.

Which chapter does this question come from in Science?

This question is from the chapter "Our Environment" in the CBSE Class 10 Science syllabus.

What topic does this question cover in Science?

This question covers the topic "Ozone Layer and How it is Getting Depleted" from CBSE Class 10 Science.

What type of question is this in the CBSE Class 10 Science 2012 paper?

This is a Very Short Answer question from Section A in the CBSE Class 10 Science 2012 paper.