CHEMISTRY RED LAB

Parts of Atom

• Proton- in nucleus and carries a positive charge has a weight of 1 amu
• Neutron- in the nucleus, it has no charge, and it carries a weight of 1 amu
• Electron- in the cloud around the nucleus, it has a negative charge
• Proton and neutron carry 99.9% of the weight in an atom

THE BEGINNING

• The first person to really get into an atom was a Greek philosopher named Democritus
• He began the search for a description of matter more than 2400 years ago
• He wondered how far can matter be divided until it can not anymore

DALTON

• Dalton layed the foundation for matter and atom research
• He discovered- All matter is made of atoms
• All atoms of one element are the same
• Compounds are 2 or more different kind of atoms
• Atoms can't be created or destroyed

DALTONS FLAWS

• atoms are indivisible not true because of neutrons, protons.
• Atoms can be smashed and broken into chips.

THOMSON THEORY

• Discovered the electron
• Model discovered due to his theory
• Plum pudding model
• Christmas pudding model
• Chocolate chip cookie model

RUTHERFORDS THEORY

• Stated that most the atom weight is in the center
• The middle only takes up 1 billionth of the volume
• The majority of an atom is empty space

BOHR'S THEORY

• Electrons orbit the nucleus
• They lose no energy and have a set way to go
• Low energy orbit closer to nucleus
• High energy are more away

CHANGES SINCE

• 1932 James Chadwick "found" the neutron
• Frederick Soddy was able to discover isotopes
• The neutron made the isotope discovery possible

CURIE

• Irene curie discovered the proton and neutron
• Did not realize the signifigance
• Ripped off by James Chadwick

MILKAN

• Proved Thomson's theory right
• mass of an electron is at least 1000 times smaller than the smallest atom.