CHEM 105 EXAM 1 PEOPLE AND
EXPERIMENTS QUESTIONS &
ANSWERS
Rutherford - Correct Answers -- experiment: shot alpha (positively charged) particles
through a gold metal foil and discovered some particles deflecting at large angles and
even back to the source
- result: most mass and positive charges are in the middle of the atom
- conclusion: the atom is made up of mostly empty space occupied by negatively
charged electrons, with a small positive charge nucleus that is most of the mass.
Dalton - Correct Answers -- came up with the atomic theory that atoms are tiny,
indivisible forms of matter.
- Law of multiple proportions: atoms combine in whole # ratios
Thompson - Correct Answers -- cathode ray experiment
- conclusions: determined the presence of electrons; the deflection by electric and
magnetic fields showed charge/mass ratio
Millikan - Correct Answers -- Oil drop experiment: suspend an oil drop in the air
- conclusion: determine the charge of an electron (negative)
Proust - Correct Answers -law of definite proportions: mass proportions are fixed, mass
ratio doesn't change
Planck - Correct Answers -- experiment: H emission spectra--light was emitted and
absorbed from Hydrogen in the same wavelengths
- results: n1 - n2 = energy of light emitted or absorbed. Get electron to move = energy of
light match the electron energy state.
- conclusion: an atom has quantized energy state that electrons can occupy, Bohr's
model of the atom
Curie - Correct Answers -- radioactivity experiment
- there are pos and neg charged particles in an atom
Lavoisier - Correct Answers -- experiment: combustion reactions
- result: weight of the container was the same before/after the rxn
EXPERIMENTS QUESTIONS &
ANSWERS
Rutherford - Correct Answers -- experiment: shot alpha (positively charged) particles
through a gold metal foil and discovered some particles deflecting at large angles and
even back to the source
- result: most mass and positive charges are in the middle of the atom
- conclusion: the atom is made up of mostly empty space occupied by negatively
charged electrons, with a small positive charge nucleus that is most of the mass.
Dalton - Correct Answers -- came up with the atomic theory that atoms are tiny,
indivisible forms of matter.
- Law of multiple proportions: atoms combine in whole # ratios
Thompson - Correct Answers -- cathode ray experiment
- conclusions: determined the presence of electrons; the deflection by electric and
magnetic fields showed charge/mass ratio
Millikan - Correct Answers -- Oil drop experiment: suspend an oil drop in the air
- conclusion: determine the charge of an electron (negative)
Proust - Correct Answers -law of definite proportions: mass proportions are fixed, mass
ratio doesn't change
Planck - Correct Answers -- experiment: H emission spectra--light was emitted and
absorbed from Hydrogen in the same wavelengths
- results: n1 - n2 = energy of light emitted or absorbed. Get electron to move = energy of
light match the electron energy state.
- conclusion: an atom has quantized energy state that electrons can occupy, Bohr's
model of the atom
Curie - Correct Answers -- radioactivity experiment
- there are pos and neg charged particles in an atom
Lavoisier - Correct Answers -- experiment: combustion reactions
- result: weight of the container was the same before/after the rxn
