Answer: CFCs (chlorofluorocarbons).
- A CFCs (chlorofluorocarbons)
- B CO<sub>2</sub>, the greenhouse gas mainly linked to global warming
- C SO<sub>2</sub>, the gas primarily responsible for acid rain formation
- D NO<sub>2</sub>, the brownish gas contributing to photochemical smog
Correct answer: A. CFCs (chlorofluorocarbons)
Explanation: Chlorofluorocarbons release Cl radicals in the stratosphere that catalytically destroy ozone (O<sub>3</sub>).
Xenon tetrafluoride (XeF4) has six electron domains around xenon — four Xe–F bonds plus two lone pairs. The lone pairs occupy opposite axial positions, leaving the four fluorine atoms in a square-planar shape (Xe–F ≈ 194 pm). Image: ChemSim, Public Domain, via Wikimedia Commons.
Concept context
Covers the nitrogen family (Group 15), oxygen family (Group 16), halogens (Group 17), and noble gases (Group 18). One of the highest-weightage inorganic chapters in NEET and JEE - includes preparation and properties of HNO₃, H₂SO₄, interhalogens, and xenon compounds.