What is an _________?

The smallest particle of an ________ that is still an ________

_________ are the building blocks of all ___________

Atomic Theory according to …THE GREEKS

Early _________ believed matter was made from the four elements of earth, ______, water and ____

Wind

Earth

Fire

Water

Atomic Theory according to …DEMOCRITUS

Greek with a different __________ on what matter was made of

Proposed that there is an _________ particle

He called the particle an atomos, which means __________ Born: 460 BC

Died: 370 BC

Atomic Theory according to …John Dalton

He performed many ___________ to understand why elements combine the way they do

Formulated the __________ Theory

His theory has been __________ to integrate the findings of other _________Born: 1766

Died: 1844

Dalton’s Atomic Theory

All substances are made of ______. Atoms are small particles that cannot be created, divided or ___________.

Atoms of the same element are exactly _________. Atoms of different elements are ___________.

Atoms join with other atoms to make ____ substances.

Atomic Theory according to …

J.J. Thomson

Discovered smaller, _______ particles inside the atom through the cathode-ray tube experiment

Born: 1856Died: 1940

Atomic Theory according to …J.J. Thomson

The particles were negatively charged particles called ___________

Dalton’s atomic theory was revised to account for electrons

Plum _________ Model of Atom

after discovery of electrons

Ernest Rutherford

He tested Thomson’s plum pudding model by aiming a beam of _________ particles at a piece of gold foil

Born: 1871Died: 1937

Atomic Theory according to …

Ernest Rutherford

Rutherford’s findings suggested that the plum pudding model was _________!

Atomic model was revised to include a _________

++++

-

--

-

______

_______

Atomic Theory according to … Neils Bohr

Suggested that _______ travel around the nucleus in a definite _____

Born: 1885; Died: 1962

Modern Atomic Theory

The current model of an atom contains a nucleus surrounded by regions called electron __________

Electrons do not travel in specific paths, and the _______ path of an electron cannot be _____________

The electron clouds are the regions an electron is likely to be _________

Electron Cloud Model

Subatomic Particles

Subatomic particle

Symbol Charge Mass Location

Proton p+ _____ _____ ______

Neutron nº ______ _____ ______

Electron e- ____________

amu_______

Cloud