Development of the Atomic Model Flashcards
1
Q
Democritis
A
- Greek Philosopher
- First to identify the possiblity of an atom because he thought that matter is made of small particles
- He named these the “ultimate” particles atomos which means indivisible
2
Q
Aristotle
A
- Dismissed Democritis’ atom idea as worthless
- Believed in reasoning instead of scientific experiments
- Said there was always a smaller piece of mater, no matter the size
- Four “elements” of earth, fire, air, water
- Theory accepted for 2000 years
3
Q
Antione Laviosier
A
Law of Conservation of Mass - Matter is not create or destroyed, just changed in a reaction
4
Q
Joseph Proust
A
Law of Definite Proportions - Always have the same proportions of elements by mass
5
Q
John Dalton
A
- Father of modern atomic theory
- Model of solid sphere
- Law of Multiple Proportions
- Developed concept of the mole
- Proposed system of symbols
6
Q
J.J. Thomson
A
- Discovered electron in 1897
- Known for plum pudding model
- Cathode ray tube experiment
- Discovered isotopes of elements
7
Q
Eugene Goldstein
A
- Discovered protons in 1900
- Anode ray experiment
- Said that since atoms contain negatively charged particles, they must also contain positively charged particles in order to remain electrically neutral
- Supported Thomson’s Plum Pudding Model
8
Q
Max Planck
A
- Founder of quantum theory
- Atoms can emit “quanta”
- Einstein used his work to study photons
- Planck’s constant
9
Q
Robert Millikan
A
- Oil drop experiment
- Measured charge of electron
- Calculated mass of electron
- Worked with Thomson
10
Q
Ernest Rutherford
A
- Discovered atoms have a small positive nucleus and remainder is empty space
- Gold Foil Experiment
- Predicted existence of neutrons
- Worked for Thomson
11
Q
Francis Aston
A
- First person to observe isotopes
- His work led Rutherford to predict the existence of the neutron
12
Q
Neils Bohr
A
- Planetary model of atom
- Electrons move around the nucleus in fixed orbits, paths or energy levels
- Spectrum lines produced when electrons move
13
Q
Erwin Schrodinger
A
- Another founder of quantum mechanics
- Famous for his equation and the cat analogy
14
Q
James Chadwick
A
- Discovered neutrons in 1932 which led to discovery of fission and the atomic bomb
- Helped with the development of the nuclear model
15
Q
Louis de Broglie
A
- Wave-particle duality theory of light meaning electrons have properties of both waves and particles
- Created a new field of physics called wave mechanics