Cathode rays originate from which particles?

Cathode rays originate from which particles?

• A. Protons
• B. Electrons
• C. Neutrons
• D. Photons

Answer: (B)

Cathode rays are streams of negatively charged particles produced when electrons are emitted from a heated cathode in a high-vacuum tube and accelerated toward the anode. This emission, called thermionic emission, creates a beam of electrons that travel as a ray and can produce a glow on a phosphor screen. Protons and neutrons are subatomic particles associated with the nucleus and are not emitted as a beam from a cathode in these devices, and photons are particles of light with no mass and are not the charged particles making up the ray. So the particles in cathode rays are electrons.

Cathode rays are streams of negatively charged particles produced when electrons are emitted from a heated cathode in a high-vacuum tube and accelerated toward the anode. This emission, called thermionic emission, creates a beam of electrons that travel as a ray and can produce a glow on a phosphor screen. Protons and neutrons are subatomic particles associated with the nucleus and are not emitted as a beam from a cathode in these devices, and photons are particles of light with no mass and are not the charged particles making up the ray. So the particles in cathode rays are electrons.