Question

What is the atomic number of Bismuth?
(A) 84
(B) 85
(C) 83
(D) 82

Answer 1

In the above question, it is asked about the atomic number of Bismuth. Atomic number of the element depends upon the number of protons present in the atom. It is a group 15 member and is present in the 6th period.

Complete step by step solution
In the question since we are asked to find out the atomic number of Bismuth. So, first let us have a look at what an atomic number is.
Atomic number is defined as the number of protons present inside the nucleus of the atom of the given elements. In a periodic table, elements are arranged according to their atomic number. In a periodic table, atoms are arranged according to their atomic number. The atomic number increases from left to right.
According to the electrons in the valence shell, the periodic table is classified into s-block, d-block, f-block and p-block.
The number of electrons present inside the nucleus of Bismuth is 83. So, its atomic number is 83. Symbolically, it can be represented as $_{{\text{83}}}{\text{Bi}}$ .
So, the correct option is option C.

Note
In a neutral atom, the atomic number of the atom is equal to the number of protons or the number of the electrons present.
In a charged ion, since the extra electrons are gained to or existing electrons are lost from the valence shell. And hence, the atomic number is equal to the number of protons but not equal to the number of electrons.
So, in general, we take atomic numbers as the number of protons present.