An element 'X' is forming an acidic oxide. Its position in modern periodic table will be

OR

Consider the following statements about an element 'X' with number of protons 13.

(A) It forms amphoteric oxide

(B) Its valency is three

(C) The formula of its chloride is $\text{XCl}_3$

The correct statement(s) is/are

This question tests the understanding of the chemical properties of oxides and the periodic classification of elements.

• Acidic Oxides: Non-metals form acidic oxides. Sulphur (Group 16, Period 3) forms $\text{SO}_2$, which reacts with water to form sulphurous acid ($\text{H}_2\text{SO}_3$).
• Amphoteric Oxides: Aluminium (atomic number 13) forms $\text{Al}_2\text{O}_3$. The NCERT text explicitly highlights that aluminium oxide and zinc oxide show both acidic and basic behaviour, reacting with both acids (like $\text{HCl}$) and bases (like $\text{NaOH}$) to form salts (like $\text{AlCl}_3$ and $\text{NaAlO}_2$) and water. This confirms statement (A). Its valency of 3 leads to the chloride formula $\text{AlCl}_3$, confirming statements (B) and (C).

Distractor Analysis:

• Option A: Group 1 elements form basic oxides (e.g., $\text{Na}_2\text{O}$), not acidic oxides. Statement (A) alone is incomplete for the OR part.
• Option B: Group 2 elements form basic oxides (e.g., $\text{MgO}$). Statement (B) alone is incomplete.
• Option C: Group 13 elements form amphoteric/basic oxides, not purely acidic. Statements (A) and (C) are correct but omit statement (B), which is also correct.