Chemistry · Periodicity of Elements and Periodic Properties
JEE Main 2026 — 23 January, Morning Shift — Question 64
The correct statements from the following are :
(A) Ionic radii of trivalent cations of group 13 elements decreases down the group.
(B) Electronegativity of group 13 elements decreases down the group.
(C) Among the group 13 elements, Boron has highest first ionisation enthalpy.
(D) The trichloride and triiodide of group 13 elements are covalent in nature.
Choose the correct answer from the otpions given below :
- Option A:
A and C only
- Option B:
A and D only
- Option C:Correct
C and D only
- Option D:
B and D only
Answer: C
Step-by-step solution
(A) Down group 13, new shells are added. Hence ionic radii of increase down the group, not decrease. So, (A) is false.
(B) Electronegativity does not strictly decrease down group 13 due to d-block contraction and irregular trends. Hence this is not strictly correct. So, (B) is false.
(C) First ionisation enthalpy generally decreases down the group. Therefore Boron has the highest first ionisation enthalpy. So, (C) is true.
(D) Group 13 trichlorides and triiodides are covalent due to high polarising power of ions. So, (D) is true.
Thus, correct statements are C and D.
Answer key and solution verified before publishing.
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- Exam
- JEE Main 2026
- Subject
- Chemistry
- Chapter
- Periodicity of Elements and Periodic Properties
- Topic
- Periodicity in Chemical Properties (Ionization Energy, Electron Affinity, Electronegativity)