Question

Iodine is a non-metal which has metallic luster.
(A) True
(B) False

Answer 1

Hint: We know that iodine is non-metal from the halogen group. And Iodine is a p-block 17th group and 5th period element. It exists in gaseous form.

Step by step solution:
Iodine is an intensely colored solid with an almost metallic luster. This solid is relatively volatile and it sublimes when heated to form a violet-colored gas.
This metallic lustre is because going down in the 17th group the size of the atom increases because of shielding effect due to which the interaction between the atom and the outermost electron of the atom decreases, and outermost electrons are loosely bound, so the electrons on the surface of iodine become excited by absorbing heat energy from light. When they release this energy and come to their normal state, they emit this light so it appears that they have a lustrous surface. This happens only in iodine halogen not in others.

So, the given statement ‘Iodine is a non-metal which has metallic luster.’ is a “True” statement.

Additional information: In case if you don’t know about metallic lusture so, metallic lustre is a water-based metallic wax that buffs to a brilliant shine. It features highly concentrated pigments and boasts an opaque coverage with only one coat. Metallic Lustre adheres to most absorbent surfaces, as well as metal.

Note: Graphite is also a non-metal which has metallic lusture. Metallic luster is due to presence of free electrons in them generally non metals don't exhibit this property, but iodine and graphite are non metals they exhibit metallic luster.