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 radioactive isotope of iodine is used for making tincture iodine, which is used as a medicine.
Answer
(a) J.J. Thomson proposed that the nucleus of an atom contains only nucleons.
False
Explanation - JJ Thomson’s model only talked about the positive and negative charges, ie, protons and electrons but didn’t mention the presence of nucleus or nucleons (subatomic particles inside nucleus)
(b) A neutron is formed by an electron and a proton combining together. Therefore, it is neutral.
False
Explanation - Proton, electron and neutron are three different and independent subatomic particles.
(c) The mass of an electron is about 1/2000 times that of a proton.
True
Explanation - Protons are around 2000 times heavier than electrons, which means the mass of an electron is about 1/2000 times that of a proton, hence mass of electron is negligible.
(d) A radioactive isotope of iodine is used for making tincture iodine, which is used as a medicine.
False
Explanation - Since tincture of iodine is the combination of 5% - 7% of iodine, water and alcohol. And the iodine used here is the ordinary iodine , that is, no radioactive isotope of iodine is present.
