Question

Which of the following is the symbol of Cobalt?
(A) $Co$
(B) $Cb$
(C) $Cu$
(D) $C$

Answer 1

As we know that cobalt belongs to d-block elements of transition metals having an atomic number of $27$ and atomic mass of $58.9g$. It has an electronic configuration of $[Ar]3{d^7}4{s^2}$and one of its isotope is radioactive and used in cancer treatments and it is also an essential component of vitamin ${B_{12}}$.

Complete answer: As we know that cobalt is a hard, silvery blue and lustrous element which belongs to d-block transition elements and possesses an atomic number of $27$ and atomic mass of $58.9g$. The symbol of cobalt is represented as $Co$.
$Cu$ represents copper which is again a d-block transition element. $C$ represents carbon and $Cb$ represent the columbium element and its name is replaced by Niobium.

Additional information: Some interesting facts about Cobalt includes:
Cobalt also has a radioactive isotope which is stable and occurs naturally and that is $^{60}CO$ which is very useful in the treatment of cancer as well as in food irradiation to prevent the pathogens from growing.
It is also an essential component found in the vitamin ${B_{12}}$ and found in trace amounts in the human body. It is also used in small doses to prevent mineral deficiencies in animals.
But when cobalt is taken in large quantities, it can be carcinogenic in humans and cobalt poisoning may take place when cobalt is ingested, breathed or comes in contact with skin accidently.

Therefore the correct answer is (A).

Note: Cobalt having chemical symbols as $Co$ seem similar to $CO$ which is carbon monoxide and commonly used as a ligand but cobalt is an element of the d-block. Cobalt is used in electroplating for its hardness and attractive appearance as well as resistance to corrosion and tolerance to high- temperatures.