MCAT Physics

Atomic Physics

MCAT Physics > Atomic Physics

Background

Bohr's Atomic Model

See Bohr's Atomic Model

Blackbodies

MCAT Atomic Physics - Black Body

Blackbodies are ideal radiators and absorbers. It would appear totally black if at a temperature lower than the surroundings because it would absorb all the wavelengths of electromagnetic radiation. They radiate an amount of energy equal to the amount they absorb but at different peak wavelengths depending on the temperature. There is one peak λ at which maximum amount of energy is emitted (not longest wavelength)

λpeakT = constant

Stefan-Boltzmann Law

Stefan-Boltzmann Law represents the energy emitted per second per unit area, which is proportional to the fourth power of the absolute temperature

ET = σT4

Photoelectric Effect

Photoelectric Effect is the all or nothing ejection of an electron from the surface of a metal in a vacuum due to an incident photon whose frequency (energy) is at least as great as the threshold frequency (fT), which depends on the metal (MCAT given). Waves with a higher frequency will have shorter wavelengths and higher energy and vice versa. This effect represents the property of light to behave as a particle because photons make one on one collisions which results in the ejection of an electron (conservation)

MCAT Atomic Physics - Photoelectric Effect

E = hf

λ = c/f

KE = hf – W

W = hfT

MCAT Physics

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