the atomic number and mass number for specimen are Z and A respectively. the number of neutrons in the atom will be:-
Answers
A = no of protons + no of neutrons
The no. of neutrons is A-Z {(no of protons + no of neutrons)-no of protons}
Explanation:
An atom with atomic number and mass number can be represented as follows.
where, A = mass number
Z = atomic number
X = atom
The atomic number represents the number of protons present in an atom. For a neutral atom, the number of protons equals the number of electrons.
Mass number represents number of protons plus number of neutrons present in an atom.
Therefore, in order to find the number of neutrons, we will subtract the atomic number (Z) from the mass number (A).
For example, an atom of carbon written as
Thus, number of protons = 6
number of neutrons = (mass number - atomic number)
= 12 - 6
= 6
Since, it is a neutral atom as it has no charge, therefore, number of electrons equal number of protons, that is, 6.