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Q21 (CDS-I/2002) 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 certain chemical elements to exist in two or more different physical forms in the same state, where atoms are bonded together in different manners [t6]. While diatomic oxygen (O2) consists of two oxygen atoms and is essential for aerobic life, triatomic ozone (O3) consists of three oxygen atoms and acts as a protective shield against ultraviolet radiation in the stratosphere [c1][c2]. These forms exhibit distinct molecular structures and chemical properties; for instance, O2 has a linear shape with a double bond, whereas O3 is a non-linear, highly reactive molecule [c2][t9]. Other common examples of allotropy include diamond and graphite for carbon [t4][t9]. They are not isotopes (which differ in neutron count), isomers (which apply to compounds with the same formula), or isobars (which have the same mass number) [t1][t3].

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] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 19: Ozone Depletion > OTSNE $$FUETION > p. 267
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