the electron Flashcards
thermionic emission
giving off electrons off a hot surface
electronvolt
the amount of energy gained or lost by electron when it moves through a pd of one volt
photoelectric effect
the emission of electrons forms he surface of a metal by electromagnetic radiation of suitable frequency
threshold frequency
frequency below which phtotemission will not occur
work function
of a metal is minumum energy needed to remove loosest electron from the surface of the metal
photon
a packet of electromagnetic energy e=hf
activity
of a radioactive substance is the number of nuclei of that substance decaying per second
law of radioactive decay
the number of nuclei decaying per second is directly proportional to the number of nuclei undecayed
nuclear fission
the splitting of large nucleus into tow smaller nuclei
nuclear fusion
the joining o two small nuclei to form one large nucleus
