Given below are two statements:
Statement (I): The first ionisation enthalpy of group 14 elements is higher than the corresponding elements of group 13.
Statement (II): Melting points and boiling points of group 13 elements are in general much higher than those the corresponding elements of group 14.
In the light of the above statements, choose the most appropriate answer from the options given below:
Statement (I): The first ionisation enthalpy of group 14 elements is higher than the corresponding elements of group 13.
Statement (II): Melting points and boiling points of group 13 elements are in general much higher than those the corresponding elements of group 14.
In the light of the above statements, choose the most appropriate answer from the options given below:
- (A)Statement I is correct but Statement II is incorrect✓ Correct
- (B)Statement I is incorrect but Statement II is correct
- (C)Both Statement I and Statement II are incorrect
- (D)Both Statement I and Statement II are correct
Answer: (A)
Solution
Across a period the increasing nuclear charge raises the first ionisation enthalpy, so each group-14 element has a higher first ionisation enthalpy than the group-13 element of the same period, and the first statement holds. For melting and boiling points the position is reversed: group-14 elements such as carbon and silicon build strong three-dimensional covalent networks and melt far higher than the corresponding group-13 metals, so group-13 elements do not in general have the higher melting and boiling points. The first statement is therefore correct and the second is incorrect.
JEE Main · 2025 · 04 Apr 2025 · Shift 2 · Single correct option