Answer : The correct option is (3) which has 9 protons, 9 neutrons and 10 electrons.
Explanation :
Atom (1) (2) (3) (4)
Number of protons 9 9 9 9
Number of neutrons 8 9 9 10
Number of electrons 9 8 10 9
The net charge 0 +1 -1 0
Protons are those which carries positive charge.
Electrons are those which carries negative charge.
Neutrons are those which do not carry any charge that means neutrons are neutral.
The net charge on an ion = Number of protons present in an ion + Number of electrons present in an ion.
Therefore, the correct option is (3) which has 9 protons, 9 neutrons and 10 electrons.