Question

$A$, $B$ and $C$ are hydroxy-compounds of the elements $X$, $Y$ and $Z$ respectively. $X$, $Y$ and $Z$ are the same period of the periodic table. $A$ gives an aqueous solution of $pH$ less than seven, $B$ reacts with both strong acids and strong alkalis. $C$ gives an aqueous solution which is strongly alkaline.
Which of the following statements is/are true?
I: The three elements are metals.
II: The electronegativities decrease form $X$ to $Y$ to $Z$
III: The atomic radius decreases in the order $X$, $Y$ and $Z$.
IV: $X$, $Y$ and $Z$ could be phosphorus, aluminium and sodium respectively.

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

Answer 1

Answer: (C)

II, IV only correct

A is acidic so it belongs to the right side of table and X belongs to the left side of table.

The electronegativities decrease from X to Y to Z.

The atomic radius increases in the order X, Y and Z and X, Y and Z could be phosphorus, aluminium and sodium respectively.

Hence, option C is correct.