Question

Identify the correct statements about Boron.
I. It has high melting point II. It has high density III. It has high electrical conductivity IV. B-10 isotope of it has high ability to absorb neutrons

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

Hint:

The isotope \(^{10}B\) is widely used in nuclear reactors because of its excellent neutron absorption ability.

Answer 1

The Correct Option is D

Step 1: Judge statement I.
Boron is a hard solid bound by a strong covalent network, which gives it a very high melting point. So statement I is correct.
Step 2: Judge statement II.
Boron is actually a low density element and is not known for high density, so statement II is incorrect.
Step 3: Judge statement III.
Pure boron behaves like a semiconductor, not a good metallic conductor, so its electrical conductivity is low at ordinary temperature. Statement III is incorrect.
Step 4: Judge statement IV.
The $^{10}B$ isotope absorbs neutrons strongly, which is why boron is used in nuclear reactor control rods. So statement IV is correct.
Step 5: Collect the correct statements.
Only I and IV are correct, while II and III are wrong.
Step 6: Choose the option.
The right combination is I and IV only, which is option (4). \[ \boxed{\text{I, IV only}} \]