Chemistry Final Flashcards
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Democritus
Democritus proposed that all matter is made up of tiny, indivisible particles called atoms.
Boyle
Boyle defined the element as a substance that cannot be broken down into two or more simpler substances by chemical means.
Joseph Priestly
discovered oxygen gas and the process of combustion.
Most important contribution
the Law of Conservation of Mass,
one of the laws is
chemical reaction
Law of conservation of mass
Lavoisier, 1794 Mass is neither created nor destroyed during ordinary chemical reactions or physical changes.
Law of definite proportions
Proust, 1799 A chemical compound contains the same elements in exactly the same proportions by mass.
Na Ci
will always be equal
law of Multiple Proportions
Dalton, 1803
When two elements, A and B form two or more different compounds, the masses of element B, that combine with a fixed mass of element A, can be expressed as a ratio of small whole numbers.
1 Theory
Daltons Atomic Theory
2 Theory
Modern Atomic Theory
Kite Experiment
concluded that there are two types of electrical charges.
Michael Faraday
Suggested that the structure of atoms is related to electricity
J.J Thompson
- Discovered the electron
- Proposed the “Plum Pudding” Model
- Determined the very large charge-to-mass ratio of -an electron
Conclusion ( J.J Thompson )
The atom is composed of negatively charged particles—Thomson named the electron.
