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.
(b) A neutron is formed by an electron and a proton combining together. Therefore, it is neutral.
(c) The mass of an electron is about $1/2000$ times that of a proton.
(d) An isotope of iodine is used for making tincture iodine, which is used as a medicine.

(a)
J.J. Thomson proposed the model of the atom that only contains electrons and protons and no neutrons. He made no mention of the nucleus or the nucleons.​

Therefore, the given statement is false.​

(b)
Neutron is not formed by an electron and a proton combining together. Neutron is an independent sub-atomic particle like electron and proton.​

Therefore, the given statement is false.​

(c)
The mass of an electron is $9.109\times {10}^{-31}kg$ (considered to be negligible) whereas the mass of a proton is $1.6726\times {10}^{-27}kg$ which is approximately 2000 times the mass of an electron.​

Therefore, the given statement is true.​

(d)
Tincture iodine is an antiseptic that usually contains 2–7% elemental I-127 dissolved in a mixture of ethanol and water. ​

Therefore, the given statement is true.​