The nucleus of an atom is composed of 4 protons and 5 neutrons. How many electrons surrounded the nucleus of this atom? 1
4
5
9

In an atom the no. of proton is equal to the no. of electron

= 4 electron

More to know - Atom is made up of Proton , neutron and electron Proton is positively charged particle , electron is negatively charged particle and neutron is neutral in charge Proton and neutron together make up nucleus and located at the centre of atom Electron revolves around nucleus No. of electron/ proton = Atomic number No. of proton + neutron = Atomic mass