Question

how does the sub-atomic particles coexist in an electrically neutral atom?

Answer 1

An atom consists three sub atomic particles
1. Protons : These are arranged in the center part of the atom called                                      nucleus.These carry positive charge.
2. Neutrons : These are also arranged in the nucleus along with protons.                                 These carry no charge.
3. Electrons : These are arranged in the shells or orbits around the nucleus.                            These carry negative charge.
Since the number of protons is equal to the number of protons in an atom, the net charge of atom is zero and hence electrically neutral.

Thus, the sub atomic particles coexist in the electrically neutral atom.

Answer 2

due to presence of equal no of protons and electrons in an atom  the net charge in the atom  becomes zero . In this way they coexist in an electrically neutral atom