On the basis of Rutherford’s model of an atom, protons (positively-charged particles) are present in the nucleus of an atom. Neutrons are neutrally-charged. Electrons, which are negatively-charged, are located outside the nucleus. Protons were discovered by Ernest Rutherford in the year 1919 when he performed his gold foil experiment. His observation and conclusion were protons exist in a nucleus and have a positive nuclear charge. The atomic number or proton number is the number of protons present in an atom. The atomic number determines an element
