4. Structure Of Atoms
Proton was discovered by Goldstein. The proton is a positively charged particle found in the atoms of all the elements. The protons are located in the nucleus of an atom. Only hydrogen atom contains one proton in its nucleus, atoms of all other elements contain more than one proton. A proton is usually represented by the symbol P+.
Characteristics of a proton
Mass of proton : The mass of proton has been found to be equal to 1.67 × 10–27 kg. This is almost equal to that of an atom of hydrogen. Since the mass of a hydrogen atom is 1 a.m.u., therefore, the relative mass of a proton is also 1 a.m.u.
Charge of proton : The charge of proton is equal and opposite to the charge of an electron. The value of charge on proton is 1.602 × 10–19 coulomb of positive charge.