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6 Cards in this Set

  • Front
  • Back
modern theory of the atom
1. electrons are like waves (they move around and make if you put a beam of electrons through a positive tube, they will make waves and paddle! against the positive charge - going through the other end!)
2. electrons are like particles (ie: when a ray of sun comes into the room you see the floating particles of dust in the air, that’s what electrons are like, little floating particles! how cute!)
3. ground state (ie: like the day before a football game, ENDOTHERMIC you absorb other people’s energy)
4. excited state (ie: during the football game, very excited..then the game is over and the excitement goes down EXOTHERMIC- goes back to ground state!)
3 subatomic particles
1. proton
*positively charged particle located in the nucleus with a mass equal to 1 atomic mass unti (amu)
2. neutron
*a particle with a neutral charge located in the nucleus with a mass equal to 1 amu
3. electron
*negatively charged particle that orbits elliptical paths (do stay with in general area but not just travelling the path) (n=principle energy level and/or periods with a mass of 2000 times smaller than mass of hydrogen)
evidence of the atom
1. law of definite composition
2. law of conservation of mass
3. law of multiple proportions
law of definite composition
a compound contained the same elements in exactly the same proportions by mass regardless of the size of the smaple or the source of the compound (source or size does not matter, should still have all the properties of water)
law of conservation of mass
when two or more elements react to produce a compound, the totaly mass of a compound is the same as the sum of masses (see worksheet)
law of multiple proportions
applies to different compounds made with the same elements- ratio for the elements that combine with a fixed mass of the other element can be expressed in while number ratios (ie: H2O and H202) --(two separate compounds are distinctly different relevant to the amt. of elements they have- if you change the ratios, you dont have the same compound)