Which of the following is not a good example of a metalloid?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Iodine
A metalloid is an element with properties between those of metals and non-metals; it may look shiny like a metal but is brittle and only a fair conductor. The common metalloids are boron, silicon, germanium, arsenic, antimony and tellurium.
Option (1) Arsenic — a metalloid of group 15, with grey metallic and yellow non-metallic forms.
Option (2) Antimony — a metalloid of group 15, silvery but brittle.
Option (3) Iodine — a halogen of group 17, a non-metal; its crystals have a metallic lustre, but it is not counted among the metalloids, so iodine is the odd one out.
Option (4) Boron — a metalloid of group 13, a hard black solid and a poor conductor at room temperature.