[Greeks] `person` believed particles could not be divided past a certain point and called these indivisible particles `name`.
person: Democritus
name: atomos

[Greeks] `person` believed matter was infinitely divisible & discredited atomos, saying that Air, Earth, Fire, Water made up the world instead. He called his matter `name`.
person: Aristotle
name: Hyle

1774: Antoine Lavoisier makes the law of `name` by burning things.
name: conservation of mass

Law of conservation of mass:
matter cannot be created or destroyed

1779: Joseph Proust makes law of `name`
name: definite proportions

Law of definite proportions: All samples of a pure compound `do` by mass. Particles of the same element are the same no matter where they come from.
do: contain the same elements in the same proportions

Law of multiple proportions: Elements combine in `a` ratios
a: whole number

1803: John Dalton makes Dalton's Atomic Theory (billiard ball model) with these postulates:
all matter is made of atoms
all atoms of an element are identical
atoms can't be divided, created, or destroyed
atoms combine to create chemical compounds
in chemical reactions atoms rearrange

Thomson used `experiment` to discover `thing` & measure mass/charge ratio.
experiment: cathode ray tube
thing: electron

Robert Millikan did the `experiment` to determine charge of electron (and mass through Thompson). 
experiment: oil drop

Thompson came up with `name` model of atom, because atoms are neutral but electrons are negative, so atom must have positive
name: plum pudding

Ernest Rutherford found out that elements have a dense nucleus and lots of empty space in `experiment` experiment by shooting `thing` at gold foil.
experiment: gold foil
thing: alpha particles

Dmitri Mendeleev made first modern periodic table, but sorted by `thing`, used it to predict elements
thing: mass

Henry Mosely used `technology` to find fixed positive charge increase between elements, created `thing`, reorganized by it
technology: x-ray spectra
thing: atomic number

Neils Bohr analyzed wavelengths of light in element, discovered electrons go in `path` with `system`
path: orbits
system: energy levels

Rutherford (later) made slits in one side of cathode ray tube and discovered `thing`
thing: proton

James Chadwick discovered `thing` with `property` and mass of proton by weighing helium atom
thing: neutron
property: no charge

Top number in isotopic notation?
mass number

Bottom number in isotopic notation?
atomic number

proton relative mass
1

electron relative mass
0

neutron relative mass
1

proton charge unit
+1

electron charge unit
-1

neutron charge unit 0

what mass spectrometer uses to seperate beam of atoms
magnet

spectrometer produces bar graph of what?
isotopes