Which plastic is used for making electrical insulation and pipes? MCQ with Answer and Explanation

Explanation:
NH₃ has a lone pair on nitrogen, which it donates to the empty 1s orbital of H⁺, forming a coordinate (dative) bond where both electrons come from nitrogen. The resulting NH₄⁺ has four equivalent N–H covalent bonds and a +1 charge. Coordinate bonds are common in complex ions: e.g., [Ag(NH₃)₂]⁺. Once formed, a coordinate bond is indistinguishable from a covalent bond.

Explanation:
Methane (CH₄) is a potent greenhouse gas, absorbing infrared radiation. Oxygen and nitrogen are diatomic and do not absorb IR. Argon is a noble gas, inert. Greenhouse gases include CO₂, CH₄, N₂O, CFCs, H₂O vapor.

Explanation:
Stratospheric ozone absorbs harmful UV-B and UV-C radiation from the sun, protecting living organisms. Depletion by CFCs increases UV at surface. Infrared is absorbed by greenhouse gases.