Unit 2 Flashcards
What was Democritus known for?
Developed the 1st ideas of atomic structure
What are the 4 components of Dalton’s Atomic Theory?
- Matter is composed of small indivisible particles
- An element is composed entirely of one type of element
- Compounds contain atoms of 2 or more different elements
- Atoms do not change their identities in chemical reactions
Who discovered the electron and what did he use to discover it?
JJ Thomson, with cathode ray tubes
Developed the Plum Pudding Model
JJ Thomson
Who conducted the gold foil experiment?
Rutherford
What were discovered in the gold foil experiment?
- Alpha particles have a helium nucleus
2. Proved existence of a positively-charged nucleus
Who discovered the nucleus?
James Chadwick (in 1932)
What is the order of the evolving atomic models?
- Democritus
- Thomson’s Plum Pudding Model
- Rutherford’s model
Ion
Atom in which there are more or less electrons than protons
What is radioactivity?
Loosing energy to gain stability
What are the types of radiation
- Alpha
particle - Beta Particle
- Gamma Particle
What are the 4 types of radioactive decay?
- Alpha Decay
- Beta Decay
3 Positron Emmision - Electron Capture
neutron symbol
^1_0 n
Proton symbol
^1_1 p
Fission
Splitting of a nucleus into smaller nuclei
Fusion
Combines 2 small nuclei to make one larger one
What temp. Is needed for a thermonuclear reaction to occur?
40,000,000K to sustain it
How many tons of coal does 1g of fission file create
3 tons of coal
How many tons of coal does 1g of fusion fuel create?
20 tons of coal
What is a half-life?
The time required for half the atoms of a radioactive nuclei de to decay.
What does a shorter half life mean?
The nuclide is less stable.
