A,B and C are oxides of elements X,Y and Z respectively. X,Y and Z are in the same period of the periodic table. A gives an aqueous solution which turns blue litmus red. B reacts with both strong acids and strong alkalies. C gives an aqueous solution which is strongly alkaline. Which of the following statement is/are true ?
(P) All the three elements are metals.
(Q) The electronegativites decreases from X to Y to Z.
(R) The atomic radius increases in the order `X lt Y lt Z`.
(S) X,Y and Z could be phosphorus, aluminium and sodium respectively.

Options

A. I, II, III only correct
B. I, III only correct
C. II, IV only correct
D. II, III, IV only correct

Answer

To solve the problem, we need to analyze the properties of the oxides A, B, and C, and the corresponding elements X, Y, and Z based on the information given.

### Step-by-Step Solution:

1. **Identify the nature of oxide A:**
- A gives an aqueous solution that turns blue litmus red, indicating that it is acidic.
- Acidic oxides are typically formed by non-metals.
- Therefore, element X must be a non-metal.

**Hint:** Remember that acidic oxides are usually associated with non-metals.

2. **Identify the nature of oxide B:**
- B reacts with both strong acids and strong alkalies, which classifies it as an amphoteric oxide.
- Amphoteric oxides can be formed by both metals and non-metals, but they are typically found in elements that are closer to the metalloid region.
- Thus, element Y could be either a metal or a non-metal.

**Hint:** Amphoteric oxides can react with both acids and bases, indicating a dual nature.

3. **Identify the nature of oxide C:**
- C gives an aqueous solution that is strongly alkaline, indicating that it is a basic oxide.
- Basic oxides are generally formed by metals.
- Therefore, element Z must be a metal.

**Hint:** Basic oxides are typically associated with metals.

4. **Evaluate the statements:**
- **(P)** All the three elements are metals: This statement is **false** since X is a non-metal.
- **(Q)** The electronegativities decrease from X to Y to Z: This statement is **true** because as we move from a non-metal (X) to a metal (Z), electronegativity decreases.
- **(R)** The atomic radius increases in the order X < Y < Z: This statement is **true** because atomic radius increases as we move from right to left across a period.
- **(S)** X, Y, and Z could be phosphorus, aluminium, and sodium respectively: This statement is **true** since phosphorus is a non-metal, aluminium is amphoteric, and sodium is a metal.

5. **Conclusion:**
- The true statements are Q, R, and S. Therefore, the correct answer is that statements Q, R, and S are true.

### Summary of True Statements:
- **(Q)** True
- **(R)** True
- **(S)** True
- **(P)** False

### Final Answer:
The correct statements are Q, R, and S.