Question

$\text{Co}$represents
A) Molecule of a compound
B) Molecule of an element
C) Atom of an element
D) One atom of carbon and one atom of oxygen.

Answer 1

To answer this question the knowledge of symbols of elements is important. The elements are symbolized by certain symbols as per either their name of their Latin name.

Complete step by step solution:
Cobalt is an element in the periodic table with atomic number 27 and atomic weight 59. It has a bluish coloured metal ion belonging to the 9th group and the 4th period of the periodic table. The symbol for cobalt is “$\text{Co}$”. Hence $\text{Co}$ represents the atom of the element cobalt. It represents an atom and not a molecule because elements remain in the atomic form only, while a combination of one or more metals is called a molecule.
The atoms of carbon and oxygen join together to form a molecule of carbon monoxide which is represented by “$\text{CO}$”, where capital ‘$\text{C}$’ is for carbon whose symbol is ‘$\text{C}$’ while “$\text{O}$” is for oxygen whole symbol is ‘$\text{O}$’.

So, the correct answer is option C.

Note:
As for cobalt, the symbol is made from the name by taking two letters from it, there are different elements that are symbolized by their Latin name. One example of it is “sodium” which is symbolized by “$\text{Na}$” after its Latin name “natrium”. The other example is mercury represented by the symbol “$\text{Hg}$” after its Latin name “hydragyrum”.
The idea of representing the elements through their symbols was decided on the basis that some of the elements had really big names and it was difficult to arrange them in the periodic table.