A neutral atom (atomic number > 1) has (a) electron and proton
(b) neutron and electron
(c) neutron, electron and proton
(d) neutron and proton.

⇒ only atom consist of 1 electron and one proton
Rest atoms greater than 1 atomic number (neutral) have neutrons,electrons and protons.

You would be correct, boiling water does disinfect contamination.    the property of disinfecting means to kill  germs, bacteria and other pathogens or contamination  that might cause an infection or cause a person to become sickly. a couple methods of disinfecting are using soap, other cleaning supplies or by simply "boiling" the contaminate.  the reason why boiling water disinfects certain attributes is because some cells cannot survive the heat and pressure.