Question

Cathode ray tube experiments

In the late 1800s, J. J. Thomson built on earlier experiments using cathode ray tubes. The radiation emitted from the cathode (negative electrode) was accelerated toward the anode (positive electrode) in these tubes and was observed to be the same regardless of the composition of the cathode. The ray could be deflected away from the negative plate of an external electrical field and toward the positive plate. The ray could also be deflected by an external magnetic field, as would be expected for a negative particle. By controlling the strengths of the externally imposed electrical and magnetic fields, the two fields can be counterbalanced and the ray passes through the fields undeflected as when no fields at all were imposed. By knowing the strengths of these fields, it is possible to determine the charge-to-mass ratio of these cathode rays or particles. Based on the data Thomson collected in his experiments using cathode rays, the concept of atomic structure was modified. Which of the following statements about the atomic structure were validated by his cathode ray experiments?
Check all that apply.

Particles of the cathode rays are fundamental to all matter.
In the atom, the particles of the cathode rays are embedded in a diffuse cloud of positive charge.
Matter contains negative charge and by inference positive charge.
There are subatomic size particles in an atom.
Cathode rays have mass.

Answer 1

Particles of the cathode rays are fundamental to all matter.

Matter contains negative charge and by inference positive charge.

There are subatomic size particles in an atom.

Cathode rays have mass.

Step-by-step explanation:

• Radiation emitted from cathode was accelerated toward the anode in tubes.

This means that the cathode rays which are travelling towards anode (positively charged) are negatively charged. Atom was considered to have subatomic particles.

C and D are correct.

• Cathode rays was observed to be same regardless of composition of cathode.

This means that particles of cathode rays are fundamental to all the matter.

A is correct.

• The rays are influenced by the magnetic and electric field and also they move a light fan when placed inside the tube.

It means that the cahrged particle has mass too.

D is correct.