Atomic Theory Flashcards
1
Q
Leucippus and his student Democritus
A
- Year: around 440 BCE
- They first proposed that everything was many of of tiny particles surrounded by empty space
- “Blind guess”
Very very old and greek
2
Q
John Dalton
A
- Year: 1808
- English
- Proposed an indivisible particle (the atom)
- Concept of atomic theory
- Atomic model
Original, old
3
Q
Joseph John Thompson
A
- Year: 1897
- English
- Discovered electrons
- Said the atom was a sphere of positive charge embedded with negative electrons (a combination of smaller + and - particles)
- Determined this by the Cathode Ray Tube experiment
- “Plum-pudding model”
Eureka moment, optimist but pretends to be a pessimist, likes worms and pudding
4
Q
Ernest Rutherford
A
- Year: 1911
- New Zealander
- Every atom has a positively charged nucleus
- Discovered with the gold foil experiment
- Mass is mostly contained in the nucleus
- Thompson’s student
- “Nuclear model”
Happy, rich, strong
5
Q
Neils Henrik David Bohr
A
- Year: 1913
- Danish
- Discovered the shells surrounding the nucleus where electrons are at large
- Nobel prize winner
- Created the current simple model of an atom
- Electrons are paired and arranged, however they can jump between shells by gaining or losing electrons.
- Also Thompson’s student
- “Planetary model”
Smart, big, bi-polar, yummy cheese
6
Q
Werner Heisenberg
A
- Year: 1926
- German
- Formulated the “uncertainty principle” (“wave equation”)
- Discovered that it is impossible to determine the exact speed and position of electrons as they move around an atom
Friends with Schrodinger, he’s a snake, lazy, uncertain principal
7
Q
Erwin Schrödinger
A
- Year: 1926
- Austrian-Irish
- Described hydrogen atoms as clouds of negative charge
- Electrons move around the nucleus in a cloud, not in orbits
- The closer to the nucleus, the higher chance there will be electrons
- Came up with the “Quantum-Mechanical Model”
Multicultural, likes Ant-Man, stormy, doesn’t like circles, likes to be close to people
8
Q
James Chadwick
A
- Year: 1932
- English
- Discovered that the nucleus also contains neutrons
- Rutherford’s student
- Mass of nucleus is around the mass of protons
Peacemaker/fair, young, expert on neutrals
9
Q
What is atomic theory?
A
- The study of the nature of atoms and how they combine to form all types of matter
- Different atoms give elements different properties