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🧪 Chemistry  ·  Environmental Chemistry  ·  NEET & JEE

The ozone layer shields living things by absorbing harmful:

Answer: ultraviolet radiation.

  • A visible light rays
  • B ultraviolet radiation
  • C infrared radiation
  • D long radio waves

Correct answer: B. ultraviolet radiation

Explanation: Stratospheric ozone absorbs most of the Sun’s damaging ultraviolet radiation.

Classical (London) SmogSources: coal burningSO₂ + particulates + fogReducing typeConditions: cold, humid,early morning, winterVisibility: very low (fog)London, 1952 - ~4000 deathsHarms: eyes, lungs, bronchitisPhotochemical (LA) SmogSources: vehicles, industriesNOx + hydrocarbons + UVOxidising typeConditions: warm, sunny,afternoon, summerProducts: O₃, PAN, acroleinLos Angeles (common in cities)Harms: eyes, rubber cracking

Classical smog is a reducing mixture of SO₂ and fog, while photochemical smog is an oxidising mixture generated by UV-driven reactions of NOx and hydrocarbons.

Concept context

Understand how human activities alter the atmosphere, water, and soil. Covers air pollutants, smog types, ozone depletion, acid rain, greenhouse effect, water and soil pollution, and the principles of green chemistry.

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