The Photo electric effect (cont'd)

• The particle description of light
• German physicist, Max Planck, purposed the following relationship between quantum of energy and the frequency of radiation
• E = h(v)
• E is the energy in joules
• v is the frequency of radiation emitted (not a v but the sign for new)
• h is the fundamental physical constant now known as Plank's constant, h=6.626 x 10^-34 [J x S]

• A photon is a particle of electromagnetic radiation having zero mass and carrying a quantum of energy
• The energy of a particular photon depends on the adiation
• E[of the photon]= h(v)

• The hydrogen atom line emission spectrum
• The lowest energy state of an atom is its ground state
• A state in which an atom has a higher potential energy than it has in its ground state is an excited state
• When investigators passed electric current through a vacuum tube containing hydrogen gas at low pressure, they observed the emission of a characteristic pink glow
• When a narrow beam of the emitted light was shined through a prism, it was separated into four specific colors of the visible spectrum
• 4 bands of light were part of what is known as hydrogen's line-emission spectrum
• Bohr Model of the Hydrogen Atom
• Niels Bohr purposed a hydrogen atom model that linked the atom's electron to photon emission
• According to the model, the electron can circle the nucleus only in allowed paths, or orbits
• The energy of the electron is higher when the electron is in orbits that are successively further from the nucleus

Homework tonight: comment on my awesome blog-age; and HW #10 pg 124, numbers 10-14