ATOMIC THEORY PROJECT

ABOUT DEMOCRITUS

• Greek philosopher that began to develop a description of the atom 2400 years ago
• Some people consider him to be the father of modern science
• Lived from 460 BC to 370 BC
• Developed his theory around 400 B.C.

DEMOCRITUS THEORY DISCOVERY

• Believed that everything is made up of atoms
• The atom was the smallest particle of matter
• Atoms are indestructible
• In motion there are a infinite amounts and kinds of atoms
• Democritus based his theory on observations

ABOUT DALTON

• John Dalton lived from 1766-1844
• Was a English Chemist with a Quaker background
• Studied color-blindness
• Also a pioneer meteorologist that kept daily records of the weather for 57 years
• His theory was developed in the early 1800s

DALTONS THEORY DISCOVERY

• Believed atoms are invisible and indestructible
• A chemical reaction is a rearrangement of atoms
• Atoms can't be created or destroyed
• atoms of different elements could be distinguished by differences in their weights.
• Which led to the discovery of compound elements

ABOUT THOMSON

• Lived from 1856–1940
• British phyiscts
• Studied the nature of electric discharge

THOMSONS ATOMIC DISCOVERY

• Discovered electrons in the atom
• This was discover in 1897
• In 1904 Thomson suggested a model of the atom as a sphere of positive matter
• In which electrons Are positioned by electrostatic forces

Plum pudding model
The Plum Pudding Model is a model of atomic structure . Thomson had discovered that atoms are composite objects, made of pieces with positive and negative charge, and that the negatively charged electrons within the atom were very small compared to the entire atom. He therefore proposed that atoms have structure similar to a plum pudding, with tiny, negatively charged electrons embedded in a positively charged substrate. This was later shown to be incorrect.

ABOUT RUTHERFORD

• British physicst
• Lived from 1871-1937
• Awarded a noble peace prize for his work

RUTHERFORD ATOMIC THEORY

• Atomic theory stated an atom had a positive nucleus
• With negative electrons surrounding it
• Most of the mass of the atom was in the nucleus and everything else was empty space
• Discovered his theory in 1911

Gold foil experiment

This experiment involved the firing of radioactive particles through thin metal foils (notably gold) and detecting them using screens coated with zinc sulfide
Rutherford found that although the vast majority of particles passed straight through the foil approximately 1 in 8000 we're deflected leading him to his theory that most of the atom was made up of 'empty space'.

ABOUT BOHR

• Lived from 1885-1962
• Earned a doctrine in physical in 1911
• Won a noble peace prize for research of atom structure
• The chemical element bohrium (Bh), No. 107 on the Periodic Table of the Elements, is named for him.
• Made his discovery in 1913

Bohr atomic discovery

Bohr was the first to discover that electrons travel in separate orbits around the nucleus and that the number of electrons in the outer orbit determines the properties of an element. His theory can be proven by calculations

Bohrs model

All the scientist contributed to the atom over time. As technology improved scientist were able to prove there theory's and every scientist added to the atom In some way. Democritus figured everything was made of atoms, dalton discovered compound elements, Thomson discovered electrons, Rutherford discovered the nucleus, and Bohr discovered electrons orbit around the nucleus. Each scientist contributed to our modern atom today.

Works cited
"J.j. Thomson Atomic Theory." Tutorvista.com. N.p., n.d. Web. 19 Jan.2014

"The Bohr Model." The Bohr Model. N.p., n.d. Web. 20 Jan. 2014

"Internet Encyclopedia of
Philosophy." Democritus []. N.p., n.d. Web. 17 Jan. 2014.

"Rutherford - Atomic Theory." Rutherford - Atomic Theory. N.p., n.d. Web. 20 Jan. 2014.

Works cited
"Dalton's Atomic Theory." Dalton's Atomic Theory. N.p., n.d. Web. 19 Jan. 2014.