Generated by claude-sonnet-4-6 · 2026-06-15 06:42 · grounding rag
Model Answer
(i) In 1987, the United Nations Environment Programme (UNEP) forged an agreement to freeze the production of CFCs at 1986 levels. This agreement is known as the Montreal Protocol.
(ii) The ozone layer shields the Earth's surface from harmful ultraviolet (UV) radiation coming from the Sun, thus protecting living organisms from its damaging effects.
Explanation
- The examiner expects the name "Montreal Protocol" and its purpose (freezing/reducing CFC production) for (i).
- For (ii), the key point is absorption/blocking of UV radiation — one clear sentence is sufficient for 1 mark. Do not confuse stratospheric ozone (protective) with ground-level ozone (pollutant).
- These answers come from Chapter 13 (Our Environment) of the NCERT Science textbook.