Match List – I (Elements in humic substances) with List – II (Concentration range):

Correct option is A

Humic substances are organic components found in soil, peat, and coal. Their elemental composition varies slightly but is generally within the following range:
· Carbon (C): 45%–55% → It forms the backbone of humic substances.
· Oxygen (O): 30%–45% → Comes from functional groups like carboxyl, hydroxyl, etc.
· Hydrogen (H): 3%–6% → Associated with organic functional groups.
· Nitrogen (N): 1%–5% → Comes from amino groups and nitrogenous compounds.
Thus, the correct matching is:
· (A) C → (I) 45–55%
· (B) O → (II) 30–45%
· (C) H → (III) 3–6%
· (D) N → (IV) 1–5%Information Booster:
· Humic substances include humic acid, fulvic acid, and humin.
· They play a critical role in soil fertility, nutrient retention, and microbial activity.
Additional Information:
· Other options incorrectly map the concentration ranges, especially for H and N, which are minor but essential components in humic matter.