Zusammenfassung der Ressource
The Electron
- Subatomic particles
- Protons
- Mass = 1 u
- Charge = +1
- Neutrons
- Mass = 1 u
- Charge = 0
- Electrons
- Charge = -1
- Mass = 1/1840 u
- Unified atomic mass unit
- Unit of mass used to express
atomic and molecular masses
- Symbol = u
- 1.66 x 10*-27 kg
- Energy of an electron
- E = qV
- E = energy
- q = charge
- V = voltage
- Measured in electronvolts
- 1 eV = 1.6 x 10*-19
- Energy conversion of a charged
particle in an electric field
- Potential to kinetic or vice versa
- qV = 1/2 mv*2
- Thermionic Emission
- The emission of electrons from the surface of a hot metal
- Work function
- Minimum energy needed to remove the
loosest electrons from the surface of a metal
- Occurs over 800 degrees C
- Cathode Ray Tube
- Components
- A vacuum inside a glass tube
- A hot filament
- An anode & a cathode
- A fluorescent screen
- Thermionic emission occurs at the cathode
- Properties of cathode rays
- Travel in straight lines
- Cause zinc sulphide to give
out light when they strike it
- They have kinetic energy
- Deflected in electric or magnetic fields
- Produce X-Rays
- X-rays
- Electromagnetic radiation of very high frequency
- Properties
- Electromagnetic waves
- Penetration
- Ionisation
- Photoelectric effect
- Emision of electrons from the surface of a
metal due to electromagnetic radiation of a
suitable frequency hitting the metal
- Photon
- Bundle of light energy
- E = hf
- E = energy
- h = Planck's constant
- f = frequency