The real harmful effect of the release of chlorofluorocarbons into the atmosphere is that it eventually causes

Step 1: Analyze the question The question asks about the real harmful effect of chlorofluorocarbons (CFCs) when released into the atmosphere.

Step 2: The concept CFCs (found in old refrigerators, air conditioners, aerosol sprays and foam) are very stable, so they drift up into the stratosphere. There, strong ultraviolet (UV) radiation breaks the C-Cl bonds and releases chlorine free radicals:

CFCl₃ → CFCl₂• + Cl•

The chlorine radicals then destroy ozone (O₃):

Cl• + O₃ → ClO• + O₂ ClO• + O → Cl• + O₂

The chlorine radical is regenerated, so one Cl• can destroy thousands of ozone molecules. This causes depletion of the ozone layer.

Step 3: Why this matters The ozone layer acts as a shield that absorbs most of the harmful UV-B and UV-C radiation from the sun. When it thins, more UV reaches the earth's surface. This leads to:

• skin cancer and cataracts in humans
• damage to crops and plankton
• other harmful effects on living things

Step 4: Check the options

• A. Excessive UV light reaching the earth's surface. Correct, this is the direct result of ozone depletion.
• B. Infrared light is related to heat and global warming (greenhouse effect), not the main ozone-related effect. CFCs are greenhouse gases, but "the real harmful effect" points to ozone depletion.
• C. CFCs are not corrosive to living things. They are fairly inert.
• D. CFCs do not cause an acidic effect. That is associated with SO₂ and NOₓ (acid rain).

Answer: A

Exam tip: Remember CFC → Cl radicals → ozone depletion → more UV. Associate "ozone" with "UV" and "CO₂/methane" with "infrared/global warming". WAEC and JAMB often test this contrast.