Dalton Thomson Schrodinger Bohr Rutherford
John Dalton • All elements are composed of atoms • Atoms are indivisible • Atoms of a given element are identical • Compounds are composed of a combination of elements. • The combination of elements in a given compound are identical • Atoms combine in set whole number ratios
J.J. Thomson • The atom is composed of a positive mass with an equal number of negative charges distributed within. • This model was called the plum pudding model whereas the sea of positive charge was the pudding and the raisins (apparently there are raisings in plum pudding) are the electrons spread throughout
Ernest Rutherford • Gold foil experiment proved that at the center of the atom was a densely positive mass. • The atoms has a center that is overall positively charged. • Surrounding the positive nucleus were tiny electrons moving in mostly empty space.
Niels Bohr • Planetary model of the atom • Most familiar with population • Bohr claimed that the electrons were located in set orbital locations around the nucleus. • Electrons could be excited to absorb and give off energy of various wavelengths.
Modern Theory • Current model of the atom. • Electrons have both particle and wave properties. • Electrons are moving in a statistically random pattern that fits a complex wave equation. • This equation is known as the Schrödinger wave equation.