Chemistry Atomic Theory Flashcards
(27 cards)
What did democritus believe?
matter isn’t infinitely divisible, it is made up of tiny particles called atoms, atoms can’t be created, destroyed, or further divided
What couldn’t democritus answer?
what holds atoms together?
Dalton’s beliefs
properties are the same of atoms of a given element, atoms of different elements differ, atoms combine in different ratios to form compounds, chemical reactions involve atoms separating, combining, rearranging themselves
What were Dalton’s experiments?
chemical reactions, studied mass ratios of elements involved in those reactions
What was Dalton wrong about
atoms being indivisible and atoms of the same element having the same masses
who worked with the cathode ray
Sir William Crookes
What did JJ Thomson first discover?
electron
What did Thomson do to discover the electron?
measure the effects of a mag and electric field on a cathode ray particle to determine it’s charge to mass ratio
Milikan?
oil drop experiment, charge of electron, mass of electron
JJ Thomson Plum Pudding Model
all matter is neutral, how do electrons exist? the model shows this
Rutherford foil experiment?
a narrow beam of alpha particles aimed at a thin sheet of gold foil
Rutherford expectations?
most alpha particles would pass through gold foil, but some deflected at large angles and some deflected right back to the source, leading to the conclusion of the positively charged nucleus and empty space in the atom
Rutherford’s flaw?
model doesn’t account for all of the atom’s mass
Who proved protons
Rutherford
Who proved neutrons
Chadwick
Bohr model incorrect?
electrons do not move around the nucleus in circular orbits, didn’t explain emission spectrum of other elements
Debroglie
particles behave like waves, particle wave equation
Heisenburg Uncertainty Principle
can’t know position and velocity of particle at the same time
what does the atomic orbital describe?
the electron’s probable location
Schrodinger wave equation
treated Hydrogen electron as a wave
Planck
energy was quantized
photoelectric effect
a photon’s energy depends on its frequency
Single replacement?
more reactive replaces less reactive
What is produced in double replacement
water, a precipitate, or a gas
