The correct statements from the following are : Choose the correct answer from the options given below :
- B and D Only
- C and D Only
- A and D Only
- A and C Only
Answer
(2) C and D Only
Solution
A. Incorrect: a new shell is added down the group, so the ionic radii of M3+ increase ( B3+ < Al3+ < Ga3+ < In3+ < Tl3+).
B. Incorrect: as per NCERT, electronegativity first decreases from B to Al and then increases marginally (B 2.0, Al 1.5, Ga 1.6, In 1.7, Tl 1.8).
C. Correct: B (801 kJ mol-1) has the highest i H1 (Al 577, Ga 579, In 558, Tl 589).
D. Correct: as per NCERT, the trichlorides, bromides and iodides of all these elements, being covalent in nature, are hydrolysed in water.
C and D only
Answer: (2)