Which of the following gases is responsible for the depletion of the ozone layer? MCQ with Answer and Explanation

Explanation:
Methane undergoes substitution reaction with chlorine in UV light: CH₄ + Cl₂ → CH₃Cl + HCl. Further substitution can give CH₂Cl₂, CHCl₃, CCl₄. This is a free radical mechanism. It does not produce methanol or ethane.

Explanation:
The enhanced greenhouse effect causing global warming is mainly due to rising CO₂ levels from fossil fuel combustion, deforestation, and industrial processes. Other GHGs like CH₄, N₂O, CFCs also contribute. Oxygen and nitrogen are not greenhouse gases. Argon is noble gas, inert. The atmospheric CO₂ has increased from ~280 ppm (pre-industrial) to over 420 ppm. This leads to climate change, sea level rise, and extreme weather.

Explanation:
Ernest Rutherford discovered the atomic nucleus through his gold foil experiment (1911). J.J. Thomson discovered the electron (1897). Chadwick discovered the neutron (1932). Bohr proposed the model of the atom with quantized energy levels (1913), not the electron. Rutherford also discovered the proton (1919). Naming discoveries correctly is important for competitive exams.