Matter Flashcards
First concept of the atom developed by
Democritus
Solid sphere or billiard ball model of atoms developed by
John Dalton
Plum pudding or raisin bun model of atoms developed by
jj thomson
Bohr or orbit model (too fixed)
niels bohr
planetary or nuclear model
Ernest Rutherford
electron clouds or quantum mechanical model
Louis de Broglie and Erwin Schroodinger
Plum pudding model…
jj thomson, discovered the electron before the proton or neutron were discovered. hypothesized that electrons were positioned uniformly inside the atom
ernest rutherford model…
majority of mass was concetrated in a minute positively charged region (nucleus) which was surrounded by electrons
Bohr model
electrons had discrete orbits which included quantum leaps when electrons moved between orbits
element is…
basic type of matter; unique properties, cannot be broken down into other elements, smallest unit of elements is an atom
compound
chemical combination of two or more types of elements
Heisenbergs uncertainty principle
it is impossible to determine the location and momentum of electrons simultaneously
principal quantum number
describes an electrons shell or energy level and the size of the orbital; further from the nucleus = higher energy level
atomic number
number of protons in the nucleus of an atom
Mass number
number of protons and neutrons in the nucleus (can change)
