Atomic History Flashcards
(25 cards)
Proposed that matter was made up of tiny indivisible particles
Democritus
Conducted combustion experiments that led to the law of conservation of matter
Antoine Lavoisier
Definite proportions
Law of constant composition- a given compound always contains the same elements in the same proportion by mass
Joseph Proust
Who’s model of an atom was a marble?
Dalton
Elements are composed of small particles called atoms
Atoms are neither created nor destroyed in a chemical reaction
Daltons atomic theory
Atoms of a particular element are identical, BUT different from atoms of all other elements
Daltons atomic theory
Discovered 2 charges
Called them positive and negative
Franklin
First related the structure of atoms to electricity
Faraday
Figured out what charges protons, neutrons, and electrons have
Faraday
A metal surface for electrons to enter/exit
Electrode
Negatively charged electrode
Cathode
Positively charged electrode
Anode
Evacuated glass tube with cathode on one end, anode on the other, electrons flow from one end to the other
Cathode ray tube
What did JJ Thomson use
A cathode ray tube
Determined the charge of the electron was negative
JJ Thomson
Plum pudding model
JJ Thomson
Who discovered radioactivity by accident? By putting uranium rock on photographic film and it developed the film
Henri Becquerel
The spontaneous emission of particles, energy, or both
Radiation
What r the 3 types of radiation?
Alpha
Beta
Gamma
A particle
Contains 2 protons and 2 neutrons
+2 charge
Alpha
Particle
-1 charge
High speed electron that is born in the nucleus
Beta
Energy (not a particle)
No charge, no mass
Gamma
Who conducted gold foil experiment?
Rutherford
What r the two conclusions Rutherford came to?
- positively charged nucleus
- Atom is mostly empty space
