?

Is there a smallest piece?

DemocritusAristotlePlatoEuclid

Hippocrates SocratesArchimedes Pythagoras

509 B.C. Rome becomes a Republic 450 B.C. Democritus and Aristotle live 350 -323 B.C. Alexander the Great Conquers

Greece 146 B.C. Rome Re-Conquers Greece 44 B.C. Julius Caesar dies…Rome becomes

Empire 1 A.D.- 315 A.D. Birth of Christ – Emperor

Constantine forms Roman Catholic Church 476 A.D. Roman Empire Falls…Dark Ages

Begin 1300 A.D. -1500 A.D. Renaissance 1492 – 1600 Age of Exploration 1650-1800 Age of Enlightenment 1803 The first experiment testing Democritus’

idea performed by John Dalton

Scientists

Charles DarwinBen FranklinIsaac NewtonLouis Pasteur

JOHN DALTON

Philosophers

Thomas JeffersonJohn LockeThomas PaineRousseauVoltaire

Sometimes called the Age of Reason…Modern Science is born

Mass is conserved when water undergoes a chemical change

The ratio of H2 to O2 gas is the same no matter how much water is used.

2H2 + O2 2H2O

John Dalton’s Observations

The Law of Conservation of Mass

The Law of Constant Composition

DALTON’S Atomic Theory

The atom exists All matter is made of

atoms Atoms are tiny,

indestructible spheres Atoms combine in

fixed ratios to form compounds

The light bends downward towards a positively charged plate on his desk!!!

Thomson’s ObservationsSomething with a negative charge comes off the atomAtoms are neutral (no overall charge)

Thomson’s ModelTiny, negatively particles called electrons are found in the atom scattered throughout like plums in puddingThe pudding is positively charged to balance out the charge

Rutherford’s observationsMost alpha particles go straight through

Very few of them bounce back at or near the direction they came from.

Rutherford’s TheoryMost of the atom is empty space, tiny electrons are found in this space.There is a tiny positive center he names the nucleus. It is the only source of positive charge in the atom.

Bohr’s observationsThe photoelectric effectColors of light given off vary by atom.

The electrons orbit the nucleus in fixed paths

The further from the nucleus the electron is the less energy is needed to knock it free

The colors of light given off are equal to the energy needed to free the electrons

Heisenberg’s ObservationsIf you know the speed of the electron you can’t know its location

If you know its location you can’t know its speed

Quantum TheoryElectrons do not move in specific paths.Electrons exist in multiple “states” at once. They don’t “pick” a state until you observe them. You can’t pin down electrons you can only say where they are likely to be.

Observations:Matter and energy seem to be interchangeable

E = mc2

Theory:Atoms are a type of vibration of a string.

Strings can vibrate lots of different ways to create all the forms of energy and matter in our universe.