Unit 1 – Chemistry Flashcard

Scientific Model 
A simplified representation of a more complex object or process which helps scientists understand the real object.
The tiny building block of all matter
Negitively charged particles
Cathode Ray Tube
A vacuum tube that Thomson used to discover electrons.
Control center of everything
Positive charged particle

Gold Foil Experiment


Was an experiment that redifined the visual of an atom
Energy Level 
Emission Spectrum
Tube that helps you understand to see the light according to Bohr’s model of the atom
Atomic Number
Number of protons in an atom.
Average Atomic Mass
The average mass of the element or atom
Mass Number
The mass of an atom in it’s own measuring system (AMU)
Different forms of an element that have a different number of neutrons
An object releases energy which travels through space then gets absorbed by another object
Ionizing Radiation
Made of matter and has particles
Energy wavelength and is not made of matter
Alpha Particles
A part of Ionizing radiation is positive. (a form -He 4/2)
Beta Particles
Ionizing radiation negative (B form -B 0/-1)
Gamma Ray
Wavelengths does nothing to nucleus. (Y form -Y 0/0)
Half life
Amount of time it takes for 50% of the atoms in a sample
Breaking apart of a nucleus
Chain Reaction
A domino effect one thing happens than another ect.
Enriched Uranium
Excess 235 Uranium more than usual
Critical Mass
The minimum amout of mass needed for the chemical reaction to start
Nuclear Reactor
A chain reaction that is controlled
Control Rods
A way to control nuclear chain reactions that absorbs neutrons 
A wau to control nuclear chain reactions by absorbing extra heat and hot energy
John Dalton 
Created the first scientific atomic theory 
JJ Thompson
Used the Cathod Ray Tube that helped him discover electrons 
Ernest Rutherford
Gold Foil Experiment, and discovered protons and a positive nucleus 
Neils Bohr
Discovered the nucleus and fixed Rutherfords model of the atom
Gold Foil Experiment
Shot alpha particles into a nucleus and the particles repelled. Thus concluding that the nucleus was positive

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