Write four characteristic properties of cathode rays

Cathode rays travel in straight lines, carry negative charge, are deflected by electric and magnetic fields, and cause fluorescence of certain materials.

Cathode rays are streams of electrons produced in a vacuum tube from the cathode. Their study led to the discovery of the electron and the development of TV and X-ray tubes.

• Straight-line travel: They cast sharp shadows of objects placed in their path.
• Negative charge: They are attracted toward the positively charged plate in an electric field.
• Deflection by fields: Electric and magnetic fields bend their path in ways consistent with negatively charged particles; deflection gives e/m values.
• Fluorescence: They make zinc sulfide and other screens glow on impact.
• Heating and mechanical effects: They can heat thin foils and spin a light paddle wheel, showing momentum.
• Ionization: They ionize gases through which they pass.
• Penetration: They can pass through thin metal foils but are stopped by thicker barriers.

Applications

• Picture tubes and oscilloscopes (deflection control).
• X-ray production when high-energy electrons hit metal targets.