Which of the following resources cannot be renewed?

Step 1: Analyze the question The question asks which resource is non-renewable, meaning it cannot be replaced naturally within a human lifetime once it has been used up.

Step 2: Explain the concept

• Renewable resources can be replaced or regenerated naturally, or through human effort, at about the rate we use them. Examples are air, water, plants, animals, and sunlight.
• Non-renewable resources take millions of years to form, so they are effectively finite. Examples are petroleum (crude oil), coal, natural gas, and mineral ores.

Step 3: Evaluate each option

• A. Air: Plants and other processes continually replenish its gases through photosynthesis, respiration, and the nitrogen and carbon cycles. It is renewable.
• B. Petroleum: It formed from the remains of tiny marine organisms buried under heat and pressure over millions of years. We use it far faster than it forms, so it is non-renewable.
• C. Food crop: We can replant and harvest crops season after season. It is renewable.
• D. Soil: Soil can be regenerated slowly by weathering and decomposition, and it can be maintained through manure, crop rotation, and fallowing. WASSCE generally treats it as renewable, or at least conservable.

Step 4: Answer Petroleum is the only resource listed that cannot be renewed within a useful time span.

Tip: Remember that fossil fuels (petroleum, coal, natural gas) and minerals are non-renewable. Anything living, or anything cycled by nature (crops, air, water), is renewable. In Nigeria, crude oil from the Niger Delta is a good example to keep in mind: once the wells run dry, it is gone.