Term
|
Definition
Matter is not infinitely divisible
Discontinuous theory of matter
Atoms move in empty space
No experiments to support the idea |
|
|
Term
|
Definition
Disagreed with Democritus and "empty space"
Continuous theory of matter
Did not have proof |
|
|
Term
|
Definition
Pseudoscience
Obsessed with turning cheap metals into gold
Some were serious |
|
|
Term
|
Definition
Beginning of modern atomic theory
Used experiments for his theory |
|
|
Term
| Law of Conservation of Mass |
|
Definition
Confirmed by Lavoisier
Matter is not created nor destroyed |
|
|
Term
| Law of Definite Proportions |
|
Definition
| A compound contains the same elements in exactly the same proportions by mass (no matter the amound present or the source) |
|
|
Term
| Law of Multiple Proportions |
|
Definition
Formulated by Dalton
When two elements form a series of compounds,the ratios of the masses can always be reduced to a whole number. |
|
|
Term
|
Definition
All matter is composed of atoms
All atoms of an element are identical
Atoms cannot be created or destroyed
Different atoms combine in whole number ratios
Atoms or one element are never changed into atoms of another element |
|
|
Term
|
Definition
Worked with evacuated glass tube
Noticed flash of light
Discovered cathode ray tube |
|
|
Term
|
Definition
Crooke's student.
Thomson believed cathode waves consisted of some type of particle
Plum Pudding Model- cookie dough |
|
|
Term
|
Definition
Passed an electric current that moved from negative to positive end.
Added another field and found moving pieces to be negative.
Used different metals and gases, but got same results
ALL atoms must contain negative particles |
|
|
Term
|
Definition
Suspended an oil drop between two plates
Calculated the charge and mass on a single electron |
|
|
Term
|
Definition
Studied under Thomson
Noticed 'alpha' particles being deflected
Gold-foil experiment |
|
|
Term
| Explain the Gold-foil Experiment |
|
Definition
-Lead block contains Uranium. Shot alpha particles through this into gold foil.
-Paticles should have continued through
-Some paticles deflected
-Particles were hitting something positive that was small, but incredibly dense |
|
|
Term
| Results of Gold-foil Experiment |
|
Definition
There was a positive particle in teh atom- proton
Came up with the nuclear model of the atom. |
|
|
Term
| What are the two regions of the atom? |
|
Definition
The Nucleus- Protons and Neutrons, + charge, almost all the mass
Electron Cloud- most of the volume of an atom, electrons |
|
|
Term
|
Definition
|
|
Term
|
Definition
Number of protons-determines kind of atom
On periodic table
Number of electrons in a neutral atom |
|
|
Term
|
Definition
Number of protons plus the neutrons
Always a whole number
NOT on the Periodic Table |
|
|
Term
|
Definition
Dalton was wrong- atoms of the same element can have different numbers of neutrons
-carbon-12 (mass number after element) |
|
|
Term
|
Definition
On the Periodic Table
Based on % abundance in nature
Called Atomic Weight
(amu)
Each isotope had different atomic mass |
|
|
