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Flashcards in atomic physics Deck (20):
1

Geiger-Marsden experiment

most of the charged particles passed through gold foil, minor scatterings

2

Rutherford's conclusions from gold foil experiment

positive charge concentrated in nucleus, and most of the mass located there. atoms are almost all empty space

3

radii of nuclei from charged particle scattering

loss of kinetic energy=gain of electrostatic potential energy

4

nuclear planetary model

Rutherford from gold-foil experiment
electrons orbit nucleus with electrostatic attraction providing needed centripetal force

5

limitations of nuclear model

electrons should be accelerating, radiating electromagnetic radiation and gradually losing energy, but this does not happen

6

atomic spectra

all objects emit electromagnetic waves, but at different wavelengths (solids mostly continuous, individual atoms don't and are characteristic of the atom)
absorption by gas at same frequencies it would emit (example of resonance)

7

experiment to find atomic emission spectra

high voltage through two electrodes at ends of sealed glass at low pressure (electrons are emitted by cathode towards anode by electric field)
diffraction grating used to disperse light into spectra

8

production of absorption spectra

a white light sent through a glass container with a low pressure gas, is then dispersed with a grating

9

fraunhofer lines

dark lines showing the elements in an atmosphere due to absorption

10

evidence for atomic energy levels

emission and absorption spectra of gases at low-pressure consist of discrete lines

11

evidence for quantization of energy in atoms

atomic spectra, when a photon is emitted, then its energy must be equal to the difference of the energy between the different electron energy states in between emissions. therefore can only take certain energy levels

12

when is a photon emitted or absorbed

emission when electrons lower energy level, or absorb when increase

13

conversion of electron volts to J

eV=1.60217657 × 10-19 joules

14

de Broglie hypothesis

since photons have momentum p=h/wavelength, he suggests all particles have wave-like properties and wavelength (wavelength=h/p=h/mv)

15

wave-particle duality

all matter and energy exhibits wave-like and particle-like properties

16

experiment verifying de Broglie's

Electron diffraction, where a maximum of electrons seen at 50 degrees suggesting constructive interference

17

kinetic energies of the atomic energy states

Ek=n^2h^2/8m(e)L^2

18

electron in a box model in origins of energy levels

the electron's probability wave has to fit boundary conditions, which leads to discrete energy levels (quantization)

19

Schrödinger's model of hydrogen atom

the electrons are given wave functions, but it has no defined position. The square of the wave-function at a point gives the probability of its location

20

Artificial transmutation

Nucleus artificially made from another