atomic model Flashcards
1800s → JJ Thomson =
electrons discovered - “plum pudding” model.
1908-1913 → Rutherford =
charged nucleus with orbiting electrons discovered - the “nuclear” model.
1914 → Bohr =
electrons in atoms travel around a central nucleus in circular orbits, protons discovered - no special name.
1932 → Chadwick =
neutrons discovered- “cloud” model.
Mass, charge and location of proton
1, +, in the nucleus
Mass, charge and location of neutron
1, 0, in the nucleus
Mass, charge, location
very small, -, electron shell
if an atom loses one or more electron it gains ….
a positive charge.
if an atom gains one or more electron it gains ….
a negative charge.
atoms of the same element can have different numbers of neutrons =
isotopes.
shiny, mostly solid, dense and strong, malleable, good heat and electrical conductors =
metals
dull, low density, weak, brittle, poor heat and electrical conductors =
non-metals
the boiling points get higher as you go down the group =
the noble gases (group 0)
have low melting and boiling point =
the alkali metals (group 1)
unreactive because their atoms have stable arrangements of electrons =
the noble gases (group 0)
