For the following statements, write T for 'True' and F for 'False'.
(a) J.J. Thomson proposed that the nucleus of an atom contains only nucleons.
► False
(b) A neutron is formed by an electron and a proton combining together. Therefore, it is neutral.
► False
(c) The mass of an electron is about 1 / 2000times that of proton.
► True
(d) An isotope of iodine is used for making tincture iodine, which is used as a medicine.
► False
