Atoms!

Democritus

came up with the earliest “atomic theory”. worked with Aristotle. Proposed that all matter is made up of tiny particles called “atomos”. (atomos= uncuttable.)

Lucretius

expanded on Democritus’s ideas. poem= “On the Nature of Things” He described the universe as composed of atoms moving through empty space.

Antoine Lavosier

Father of Modern Chemistry, made a list of 33 elements. helped to develop the metric system. he died from being guillotined during the French Revolution. Introduced The Law of Conservation of Mass.

The Law of Conservation Mass

states that matter cannot be created/destroyed, only rearranged.

Elements

pure substances made of 1 kind of atom.

John Dalton

Born in England, developed the modern “Atomic Theory”.

John Daltons modern atomic theory:

states that each element is made of unique atoms combine in fixed ratios to form compounds.

compounds

2 or more different atoms that are chemically combined.

JJ Thomson

England, discovered the electron. Invented the “Plum Pudding Model”.

electron

subatomic particle with a negative charge.l

Plum Pudding Model

explains what an atom looks like. Pudding= atom with a + charge, Dried fruit= scattered - charge atoms. states the electrons are embedded in a positively charged sphere.

Ernest Rutherford

Born in New Zealand, Father of Nuclear Physics. discovered the nucleus. Invented the Gold Foil Experiment.

Gold Foil Experiment

shows that atoms have a small, dense, + charged center called the nucleus. performed by shooting marbles at a thin sheet of gold that must go through, this shows most of the atom is empty space.

nucleus

most f the mass of an atom. electrons orbit the nucleus.

alpha particles

tiny + charged, made of 2 protons (+) / 2 neutrons (0, no charge) that come from radiative elements (radium).

Neils Bohr

Born in Denmark, made the “Bohr Model”, he refined Rutherford’s model. Introduced energy levels for electrons, described how they go around the nucleus in orbits.

Bohr Model

described how electrons travel around the nucleus is orbits / electrons can jump levels.

Marie Curie

research in radioactivity, helps us to understand atomic structure.

radioactivity

nucleus gives pff energy in the decaying process, this gets rid of extra energy to “calm down”

Erwin Schrodinger

Nature of Electrons, he proposed the Quantum Mechanical Model.

Quantum Mechanical Model

describes electrons as existing in “clouds”, not in fixed orbits.

James Chadwick

worked on the Manhattan Project, discovered the neutron (0).

Manhattan Project

Fat Man and Little Boy nuclear bombs.