Question

Assertion: The fluorine has lower reactivity.
Reason : $F-F$ bond has low bond dissociation energy.

• A. Both assertion and reason are true and the reason is a correct explanation of the assertion
• B. Both assertion and reason are true but reason is not a correct explanation of the assertion
• C. Assertion is true but reason is false
• D. Both the assertion and reason are false
• E. Assertion is false but the reason is true

Answer 1

Answer: (E)

Fluorine have the highest electronegativity of all the elements because it has the largest nuclear charge and the least atomic shell, so it has the largest nuclear pull force. In other words, fluoride has the strongest ability to pull or catch an electron to form negative ion (that is, electronegativity).

Bond dissociation energy of $F_2$ is fairly low due to the lone pair - lone pair repulsions of the two flourine atoms, which are placed so close to each other due to small size of the atom.