b) Figure 8 shows different graphs of the same wave motion.

i) Define environmental pollution. Environmental pollution is the introduction of harmful substances or contaminants into the natural environment, causing adverse changes to air, water, or land quality.

ii) Name a common source of chlorofluorocarbon (CFC) in homes. A common source of CFCs in homes is old refrigerators or air conditioning units.

iii) State one negative effect of CFCs to the environment. CFCs cause the depletion of the ozone layer, which leads to increased ultraviolet (UV) radiation reaching the Earth's surface.

iv) Plastics are non-biodegradable. What is a non-biodegradable substance? A non-biodegradable substance is a material that cannot be naturally broken down or decomposed by microorganisms (like bacteria and fungi) into simpler, harmless substances over time.

v) State one environmental problem associated with the poor disposal of plastics. One environmental problem is land and water pollution, which can harm wildlife (e.g., marine animals ingesting plastic) and clog drainage systems, leading to flooding.