The Electron

True or false; an electron has a charge of exactly 1 Coulomb

• True

• False

Who gave the electron its name?

• Rutherford

• Faraday

• Stoney

• Einstein

Why was this experiment important?

• it artificially accelerated atoms

• it proved that an atom was made up of a small dense centre

• it proved the existance of x-rays

• it measured the charge on an electron

Who carried out this experiment?

• Millikan

• Rutherford

• Stoney

• Watt

What is thermionic emission?

• the emission of electrons from the surface of a hot metal

• the emission of electrons when light of a certain frequency falls on a metal

• heat being converted into light energy

• the heating up of electrons

What is the role of the filament in a cathode ray tube?

• to accelerate electrons

• to supply current to the cathode

• to heat the cathode

• to direct the electrons

What causes the electrons to be accelerated across the cathode ray tube?

• The high voltage between the anode and the cathode

• Thermionic emission

• The hole in the anode

• The fluorescent screen

Electrical potential energy can be calculated using

• V = IR

• E = 1/2 mv²

• Q = CV

• E = Vq

What are X-rays?

• emitted by unstable isotopes

• electrons

• electromagnetic radiation

• particles

How are x-rays produced?

• when we reach the breakdown voltage

• when unstable isotopes decay

• when light energy gets converted into kinetic energy

• when high-energy electrons in a cathode ray tube strike a metal target