Question

In which of the following boron and boron related substances are not correctly matched with the application shown against it?

• A. Boron fibres -- manufacture of glass wool
• B. Metal borides -- protective shields in nuclear industry
• C. Borax -- flux for soldering metals
• D. Boric acid -- mild antiseptic

Hint:

NCERT Facts: Boron fibres \(\rightarrow\) Aerospace materials Borax \(\rightarrow\) Flux Boric Acid \(\rightarrow\) Mild antiseptic Metal Borides \(\rightarrow\) Nuclear shielding

Answer 1

The Correct Option is A

Step 1: Know what the question asks.
We are given four pairs of a boron substance and its use. We must find the pair that is wrongly matched. So we check the real use of each item.
Step 2: Check boron fibres.
Boron fibres are very strong and light. They are used in aircraft and aerospace as strong composite materials. They are not used to make glass wool. So this match is wrong.
Step 3: Check metal borides.
Metal borides absorb neutrons well, so they are used as protective shields in the nuclear industry. This match is correct.
Step 4: Check borax.
Borax is used as a flux for soldering metals. It cleans the metal surface by removing oxide layers so solder sticks well. This match is correct.
Step 5: Check boric acid.
Boric acid is a weak acid used as a mild antiseptic, for example in eye washes. This match is correct.
Step 6: Pick the wrong one.
Only the boron fibres pairing is wrong. So the incorrectly matched option is \[ \boxed{\text{Boron fibres -- manufacture of glass wool}} \]