French Chemist Antoine Laurent Lavoisier developed a systematic means
of describing the atomic theory. 
Laviosier
did experiments with fire and logs in a closed environment to show that
all the matter that he started with remained. The fire simply caused chemical
reactions to occur which changed the form of the matter. In his experiments
the mass remained the same throughout the reaction - no matter was lost
and all the atoms remained the same. In 1789, Lavosier wrote a chemistry
textbook intitled, "Elements of Chemsitry".The equipment set-up for Lavoisier's
experiments with fire and logs.
In
1803, the english chemist John Dalton theorized that atoms of different
elements were diffferent from each other. Dalton's theory is known as the
atomic theory of matter. Dalton came to this conclusion after finding that
in chemical reactions, elements of the same compounds also appeared in
the same ratios. The consistency of ratios for each compound has been labeled
the "Law of Multiple Proportions". For example, every compound of
water has 2 hydrogen atoms and 1 oxygen atom.Dalton provided the first
model for atomic theory.
|
|
| 1. All matter is made up of atoms. |
| 2. Atoms of the same element have the same properties and atoms of different elements have different properties. |
| 3. Atom's cannot be created, divided or destroyed.* |
| 4. Atoms of different elements combine to form compounds inwhole number ratios. |
| 5. In chemical reactions, atoms can be rearranged, combined or seperated. |
In the 1930's scientist determined that the particles of the atom's nucleus were hedl together by a force they called "strong force". This strong force only exerts force 10-15 meters or the diameter of a nucleus.
Atoms are so small that scientist first saw a single atom in 1980. They used a device called a scanning electron microscope.
|
|
|
|
|
|
|
|
|
| Atoms | Periodic Table of Elements | Nucleus | Proton | Neutron | Electron |
|
|