Q: Which one of the following statements is correct ?
(a)A neutron is formed by combination of an electron and a proton. Therefore, it is neutral
(b)The mass of an electron is about 1/2000 times that of a proton
(c)An isotope of cobalt is used in the treatment of goiter
(d)J. J. Thomson proposed that the nucleus of an atom contains only neutrons
Answer pending verification