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Q87 (NDA-I/2009) Science & Technology › Basic Science (Physics, Chemistry, Biology) › Basic chemical principles Answer Verified

Oxygen and ozone are

Result
Your answer: —  Â·  Correct: A
Explanation

Oxygen (O2) and ozone (O3) are allotropes of the element oxygen. Allotropy refers to the property of some chemical elements to exist in two or more different forms in the same physical state, known as allotropes [t5]. While dioxygen (O2) consists of two oxygen atoms and is essential for life, ozone (O3) is a triatomic molecule consisting of three oxygen atoms [c1][c3]. These forms differ in their molecular structure and chemical properties; for instance, ozone is a highly reactive gas that acts as a protective shield against ultraviolet radiation in the stratosphere [c4][c5]. They are not isomers because they have different molecular formulas, nor are they isotopes or isobars, which relate to variations in atomic nuclei (neutrons and mass numbers) rather than molecular bonding [t2][t7].

Sources

  1. [1] Science , class X (NCERT 2025 ed.) > Chapter 13: Our Environment > 13.2.1 Ozone Layer and How it is Getting Depleted > p. 212
  2. [2] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 20: Earths Atmosphere > Ozone (O3) > p. 272
  3. [3] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 19: Ozone Depletion > OTSNE $$FUETION > p. 267
  4. [4] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 1: BASIC CONCEPTS OF ENVIRONMENT AND ECOLOGY > Structure of the Atmosphere > p. 7
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