Electron Configuration of Nitrogen:
Nitrogen (N) has an atomic number of 7, which means it has 7 protons and 7 electrons in its neutral state. The electron configuration of nitrogen is 1s^2 2s^2 2p^3, which means it has two electrons in the 1s orbital, two electrons in the 2s orbital, and three electrons in the 2p orbital.

N3- ion:
When nitrogen gains three electrons, it forms the N3- ion. The negative charge indicates that it has gained three electrons to achieve a stable configuration. Let's determine the number of electrons, protons, and neutrons in the N3- ion.

Number of Electrons:
The N3- ion has three additional electrons compared to the neutral nitrogen atom. Since the neutral nitrogen atom has 7 electrons, the N3- ion will have 7 + 3 = 10 electrons.

Number of Protons:
The number of protons in an atom or ion remains the same. Therefore, the N3- ion will still have 7 protons.

Number of Neutrons:
The number of neutrons can be calculated by subtracting the number of protons from the mass number (total number of protons and neutrons). The mass number of nitrogen is the sum of protons and neutrons, which is 7 + 7 = 14 in this case. Since the N3- ion has the same number of protons as the neutral nitrogen atom, the N3- ion will also have 14 - 7 = 7 neutrons.

Summary:
In the N3- ion:
- Number of electrons: 10
- Number of protons: 7
- Number of neutrons: 7

3- indicates 3 Electrons are added so
no of protons=7
neutrons =7
electrons=10