Discovery of Sub-Atomic Particles
Discovery of Sub-Atomic Particles: Overview
This topic covers concepts, such as, Subatomic Particles, Discovery of Electron, Mass of a Neutron & Charge on a Neutron etc.
Important Questions on Discovery of Sub-Atomic Particles
Which of the following is never true for cathode rays?

Protons are discovered by Goldstein's experiment.

Protons are discovered by

In Millikan's experiment, static electric charge on the oil drops has been obtained by shining -rays. If the static electric charge on the oil drop is , calculate the number of electrons present on it.

Among the following, the correct statement about cathode ray discharge tube is

Which of the following will not show deflection from the path on passing through an electric field? (Proton, cathode rays, electron, neutron)

Which of the following substances, shows the properties of phosphorescent?

The electrical discharge through the gases could be observed only at

and are isotones whereas and are isotopes.

Millikan measured the mass of an electron by performing the oil-drop experiment in the laboratory.


Neutrons can be found in all the atoms.

The ratio of specific charge of an electron to that of a proton is

Cathode rays are produced from the _____ in a discharge tube. (Cathode/ anode)

Deuterium nucleus contains

A certain photochemical reaction is found to require 8.1 x 10-19energy per water molecule.
Calculate the number of photons (per water molecule) of light with wavelength of 2.21x 10-6 mthat is required to initiate the reaction​ ?

What are cathode rays?

The ratio of specific charge of an electron to that of a hydrogen ion is

The mass of neutron is of the order of which of the following?

The relative charge on an atom having protons, neutrons and electrons is:
