Here we have to choose the atom which has same number of neutrons as 14N
The atom which has same number of neutrons as 14N among the given atoms is (D) 13C
We know, in an atom the number of electrons (atomic number) is equivalent to the number of protons. For nitrogen (N), the number of electron is 7. Thus the number of protons present in the nucleus is also 7 to make the atom uncharged.
The mass number of the atom is the number of the neutrons + number of the protons. In 14N there are 7 protons and 7 neutrons.
Thus among the given atoms the atom which has 7 neutrons will have the same number of neutrons.
A) Now in 16O the atomic number is 8 and mass number is 16. Thus the number of protons and neutrons are each 8 units.
B) In 15N, the atomic number is 7 but mass number is 15, thus number of protons and neutrons are 7 and 8 respectively.
C) In 14P the atomic number is 15 but mass number is 14, so number of protons and neutrons are 15 and -1 (not exist) respectively.
D) In 13C the atomic number is 6 and mass number is 13. So the number of protons are 6 and number of neutrons are 7.
Thus the correct answer will be D) 13C.