20-12-2012, 12:23 PM
STRUCTURE OF ATOM
[attachment=44544]
HISTORY OF THE ATOM
Democritus develops the idea of atoms
He pounded up materials in his pestle and mortar until he had reduced them to smaller and smaller particles which he called
John Dalton
Suggested that all matter was made up of tiny spheres that were able to bounce around with perfect elasticity and called them
Joseph John Thompson
Found that atoms could sometimes eject a far smaller negative particle which he called an
THOMSON’S MODEL OF ATOM
Thompson develops the idea that an atom was made up of electrons scattered unevenly within an elastic sphere surrounded by a soup of positive charge to balance the electron's charge like plums surrounded by pudding.
SUMMARY
The Atomic Number of an atom = number of
protons in the nucleus.
The Atomic Mass of an atom = number of
Protons + Neutrons in the nucleus.
The number of Protons = Number of Electrons.
Electrons orbit the nucleus in shells.
Each shell can only carry a set number of electrons.
[attachment=44544]
HISTORY OF THE ATOM
Democritus develops the idea of atoms
He pounded up materials in his pestle and mortar until he had reduced them to smaller and smaller particles which he called
John Dalton
Suggested that all matter was made up of tiny spheres that were able to bounce around with perfect elasticity and called them
Joseph John Thompson
Found that atoms could sometimes eject a far smaller negative particle which he called an
THOMSON’S MODEL OF ATOM
Thompson develops the idea that an atom was made up of electrons scattered unevenly within an elastic sphere surrounded by a soup of positive charge to balance the electron's charge like plums surrounded by pudding.
SUMMARY
The Atomic Number of an atom = number of
protons in the nucleus.
The Atomic Mass of an atom = number of
Protons + Neutrons in the nucleus.
The number of Protons = Number of Electrons.
Electrons orbit the nucleus in shells.
Each shell can only carry a set number of electrons.