Question

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 $\frac{e}{m}$ of electrons is much greater than the $\frac{e}{m}$ of protons
• D. The $\frac{e}{m}$ ratio of the cathode ray particles changes when a different gas is placed in the discharged tube

Answer 1

Answer: (A), (C)

The correct options are
A Cathode rays are streams of negatively charged ions
C The $\frac{e}{m}$ of electrons is much greater than the $\frac{e}{m}$ of protons

Thomson's experiment revealed that cathode rays are composed of negatively charged particles called electrons. He also determined that the charge to mass ratio of electrons which was much greater (about 2000 times) than that of proton.

So, both A and C are correct.