Atomic Structure Flashcards
Which scientist found evidence for the existence of neutrons and in what year?
James Chadwick, 1932
What was the name of the scientist who suggested the plum pudding model?
JJ Thomson
What did Ernest Rutherford direct at a thin gold leaf in 1905?
Alpha particles
The Rutherford scattering experiment proved the existence of…
Nuclei
What did Niels Bohr add to the Rutherford atomic model and in what year?
That electrons orbit the nucleus at specific distances (shells) , 1913
JJ Thompson discovered what subatomic particle and in what year?
Electron, 1897 using a cathode ray tube
What did the plum pudding model look like?
A ball of positive charge with negatively charged electrons embedded in it.
What were atoms thought to be BEFORE the discovery of the electron?
Tiny spheres that could not be divided
What was the conclusion of the alpha particle scattering experiment?
The mass of an atom is concentrated at the centre (nucleus) and that the nucleus had a charge
The alpha scattering experiment replaced the…
plum pudding model
what is activity and what is it measured in?
the rate at which a source of unstable nuclei decays, becquerels (Bq)
What is count rate and how is it measured?
Decays per second recorded by a Geiger-Muller tube
what is radiation dose measured in?
sieverts (Sv)
What is irridation?
the process of exposing an object to a source of nuclear radiation
what can irradiation be used for?
to sterilise or kill bacteria on things that cannot be heated (gamma rays)
