chap 4 atomic structure Flashcards
(25 cards)
democritus
the idea of the atom
john dalton
first atomic theory
what was the first atomic theory?
- atoms
- elements are the same
- compounds
- reactions
j.j. thomson
electron
what did j.j. thomson invent/use?
cathorade tube
what is the mass of an electron?
1/1860 mass of hydrogen
aristotle
matter is continious
ernest rutherford
discovered the nucleus
what did rutherford shoot through gold foil?
alpha particles
what is an alpha particle?
helium nucleus
robert miliken
invented the oil drop experiment
niels bohr
planetary model “bohr diagram”
james chadwick
discovered neutrons
what is the mass of a proton?
1/12 12C isotope
what is the atomic number?
number of protons in an atom
what is a negative charged electron?
negative = anion
what is a positive charged electron?
positive = cation
mendeleev
listed elements by atomic mass
what is the modern periodic table listed by?
atomic number
henry mosley
listed periodic table according to increasing atomic number
what is the diff between periods and groups?
periods : horizontal rows
groups : vertical columns
quantum theory
describes and predicts behavior of electrons in an atom
Heisenberg’s uncertainty principle
it is impossible to know exactly the velocity and position of a particle at the same time
Robert Millikan improved the work of Thomson by describing both the
charge and mass
