J.J. Thomson's cathode-ray tube experiment demonstrated that (a) cathode rays are streams of negatively charged ions (b) all the mass of an atom is essentially in the nucleus (c) the e/m of electrons is much greater than the e/m of protons (d) the e/m ratio of the cathode-ray particles changes when a different gas is placed in the discharge tube

Answer: (c). Thomson measured e/m of cathode-ray particles and found it the same for every gas, so (d) is wrong. Cathode rays are electrons, not ions, so (a) is wrong; the nucleus was found later by Rutherford, so (b) is wrong. The measured e/m was about 1800 times that of the hydrogen ion (proton). So the answer is (c).

J.J. Thomson's cathode-ray tube experiment demonstrated that | NEET 2003 (AIPMT)

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Cathode Rays, Thomson's Experiment & Gas Discharge

J.J. Thomson's cathode-ray tube experiment demonstrated that

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Answer: (c)

Thomson measured $e/m$ of cathode-ray particles and found it the same for every gas, so (d) is wrong.
Cathode rays are electrons, not ions, so (a) is wrong; the nucleus was found later by Rutherford, so (b) is wrong.
The measured $e/m$ was about 1800 times that of the hydrogen ion (proton).
So the answer is (c).

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