- Find the number of Protons and Neutrons in the nucleus of an atom of an element x which is represented as 207 X 82
The atomic number of an element is equal to the number of protons in an atom. This is equal to the number of electrons in a neutral atom. Also, mass number is the total number of protons and neutrons that are present in an atom. Whenever we represent an atom, the atomic number is represented as the subscript and the mass number is represented as the superscript. For the given atom,
207 X 82
82 is written as the subscript and 207 is written as the superscript. So the number of protons are 82. The total number of protons and neutrons (mass number) are 207, so the number of neutrons will be
= mass number - atomic number
= (207 - 82) = 125
So the number of protons are 82 and number of neutrons are 125.