Question

In terms of chemical composition, arrange the elements found in red and yellow soils in descending order of their percentage-

• [(J)] Iron

• [(K)] Magnesium

• [(L)] Insoluble elements

• [(M)] Aluminium
Choose the correct option-

• A. $ \text{K} \rightarrow \text{L} \rightarrow \text{M} \rightarrow \text{J} $
• B. $ \text{L} \rightarrow \text{J} \rightarrow \text{M} \rightarrow \text{K} $
• C. $ \text{J} \rightarrow \text{K} \rightarrow \text{M} \rightarrow \text{L} $
• D. $ \text{M} \rightarrow \text{J} \rightarrow \text{L} \rightarrow \text{K} $

Hint:

In red and yellow soils, remember the simple trend: Silica (insoluble) dominates first, iron gives color, aluminium is moderate, and magnesium is minimal due to heavy leaching.

Answer 1

The Correct Option is B

Step 1: Identify the items.
We must rank, by percentage in red and yellow soils, the parts: (J) Iron, (K) Magnesium, (L) Insoluble elements, (M) Aluminium.
Step 2: Recall how these soils form.
Red and yellow soils are heavily weathered tropical soils where leaching washes away the soluble bases.
Step 3: Find the dominant fraction.
What resists weathering, mainly silica and quartz, the insoluble elements (L), remains the largest share.
Step 4: Place iron and aluminium.
Iron oxides (J) give the red and yellow colour and form the next biggest part, followed by aluminium (M) in clay minerals.
Step 5: Place magnesium last.
Magnesium (K) is a mobile base that leaching removes, so it is present only in trace amounts and ranks lowest.
Step 6: Assemble the descending order.
This gives $\text{L} \rightarrow \text{J} \rightarrow \text{M} \rightarrow \text{K}$, which is option B.
\[ \boxed{\text{L} \rightarrow \text{J} \rightarrow \text{M} \rightarrow \text{K}} \]