Given below are two statements :
Statement I: Boron is extremely hard indicating its high lattice energy
Statement II : Boron has highest melting and boiling point compared to its other group members.
In the light of the above statements, choose the most appropriate answer from the options given below
Statement I: Boron is extremely hard indicating its high lattice energy
Statement II : Boron has highest melting and boiling point compared to its other group members.
In the light of the above statements, choose the most appropriate answer from the options given below
- (A)Statement I is incorrect but Statement II is correct
- (B)Both Statement I and Statement II is correct✓ Correct
- (C)Statement I is correct but Statement II is incorrect
- (D)Both Statement I and Statement II is incorrect
Answer: (B)
Solution
Boron is a three-dimensional covalent solid built from icosahedra joined by strong, directional covalent bonds. This network gives it a very high lattice energy and makes it extremely hard, so the first statement is correct. The same rigid covalent bonding gives boron the highest melting and boiling points of any group element; the heavier members, with increasingly metallic and weaker bonding, melt and boil at lower temperatures, so the second statement is also correct. Both statements are correct.
JEE Main · 2023 · 12 Apr 2023 · Shift 1 · Single correct option