Study Flashcards
Aristotle
Disagree with Democritus
Believe matter was continuos
Cause chemistry to die
Alchemist
Believed in 4 classical element
Try to make gold n elixir of life
Lead to discovery of atom
Robert Boyle
Perform quantitive experiment
Use number
Measure relationship btn mass n volume
Georg Stahl
Phlogiston float out of burning material-wrong
Led to thought of decreasing mass going into air
Antoine Lavoisier
Created Law of Conservation of Matter~matter can be neither created nor destroyed
Published a Chemistry book in 1789
“Elementary Treatise on Chemistry”
Executed same year
Joseph Proust
Created Law of Constant~ given compound always contains same elements in the same proportions of mass
John dalton
Created the atomic theory of matter from putting together different ideas n made this as a basis for his book
Study chemistry, meteorology, color blindness
Atomic Theory of Matter
1) All matter is composed of extremely small particles called atom (Democritus)
2) Atoms of a given element r identical in size, mass, n other properties: atoms of different elements differ (Dalton technically is wrong b/c he is not aware of isotopes)
3) Atoms cannot be subdivided, created, or destroyed (Antoinne Lavoisier’s Law of Conservation of Matter)
4) Atoms of different elements combine in simple whole # ratios to form chemical compounds (Joseph Proust)
5) In chemical reaction, atoms r combined, separated or rearranged (none made it)
Democritus
Greek philosopher
Propose all matter in universe is composed of small particle(atomos~indivisible)
Michael Faraday
Relate to electricity
Suggest particles of atoms was related to electricity
J.J.Thompson
Research cathode ray tubes
Corpuscle (electron) ~ partially evacuated glass tubes lined w/ fluorescences in the presence of electricity
Magnet push electrical field = quantitative strength of magnet n amount of deflection, distance of electron travel
Measure deflection n based on charge calculated on electric charge per mass of the electron -1.76x10^8 column per gram
Strength of magnet = charge to mass ratio per deflection (charge/mass)
Plum pudding model
Robert Millikan
Measure charge of electron
Use charge to mass ratio to calculate mass of an electron at 9.11x10^-25g
Charge equals 1.60x10^-19 coulumb
Henri Becquerel
Studied uranium material (pitchblende)
It cause exposure to photographic paper
Spontaneously emit high energy radiation
Marie n Pierre Curie
Follow Henry Becquerel n help study same thing
Study discovery of polonium n radium
Maria got Noble Prize
Found radioactive therapy n X-ray
Ernest Rutherford
Father of radiation
Discover 2 type of radiation
Beta Rays: electrons attracted to a + plate
Alpha Rays: protons attracted to a - plate
Gama Rays: similar to X-ray: not particles
Try to prove J.J.Thomson model is correct
Why on rare occasion + alpha particle bounce
