electron and nucleus Flashcards
Properties of electron
negative charge, small mass
How are electrons produced in x ray tube
thermionic emission
How are electrons accelerated in x ray tube
High voltage
Property of tungsten
high melting point
Thermionic emission
Emission of electrons from surface of a hot metal
photoelectric effect
Emission of electrons from the surface of a metal due to electromagnetic radiation of suitable frequency hitting the metal
GJ stoney
Irish, named electron
JJ Thompson
Used Stoney’s theory to help discover sub atomic particles
Robert Millikan
Discovered charge on electron in oil drop expt
Main component of oscilloscope
Cathode ray tube
Apparatus of cathode ray tube
Glass evacuated tube, thin filament, 2 electrodes, florescent screen
Properties of cathode rays
Travel from cathode in straight lines, deflected in electric or magnetic field, produce x rays when strike heavy metals
Applications of cathode ray tubes
Old tv screens, cathode ray oscilloscope
X rays
electromagnetic waves of high frequency
Half life
Time taken for half the nuclei in a radioactive sample to decay is constant
Application of half life
Carbon 14 dating
Mass vs atomic mass number
mass is protons and neutrons, atomic is protons
Isotope
Variation of same element with a different number of neutrons in the nucleus
Rutherford
Alpha scattering expt, showed that atom had a central core of positive charge w electrons a good distance outside
Bequerel
Discovered radiation, detected it w electroscope
Function of control rods
Absorb neutrons to reduce rate of production of energy
Function of moderator
Slows down neutrons released by fission to speeds at which they are likely to cause further fission
Coolant
Removes energy to heat exchanger where steam turns turbines
Fuel rods
Contain uranium, whose nuclei undergo fission and release energy
