Modern Atomic Theory Electrons in the Atom Electromagnetic Spectrum. Fundamentals of Light. Neon advertising signs are formed from glass tubes bent in various shapes. An electric current passing through the gas in glass tube makes the gas glow with its own characteristic color.
The ground state is the lowest energy level that an electron can occupy.
The excited state is a higher energy level that an electron may move to after absorbing energy.
The amount of energyabsorbed by the electron is equal to the energy of the photon which is emitted.
A quantum leapis the jump in energy level that an electron will make after absorbingthe correct quanta of energy.
A quantum is a packet of energy that electrons absorb to change energy levels.
Light (photons): form of some of the electromagnetic radiation (energy) released by electrons as theyreturnto their ground state from their excited state.
(where electrons are suppose to be)
Sun gives tremendous amount of energy (ground excited)
(goes to a higher e- level)
Lights off Ground state
Lights on excited state
(always little bursts of energy going on)
Electromagnetic radiationis a form of energy that exhibitswavelikebehavior as it travels through space.
The Electromagnetic Spectrum
In increasing energy, ROYGBIV
Long wavelength --> small frequency (low energy)
Short wavelength --> high frequency (High energy)
Used by military ( to see in drk)
Every object with a temperature above absolute zero radiates in the infrared.
a) Prism (curve each wave length)
A spectroscope: device used to view the visible wavelengths of light produced by different atoms.
The wavelengths are visible as bright lineson the spectrum.
ROY G BIV
Insects can see uv waves
Radiation treatment using radioactive cobalt-60.
The particular wavelength of light produced is specific for each element and can be used to identify it.
Slit that allows light inside
Line up the slit so that it is parallel with the spectrum tube (light bulb)
A flame test : method used to identify and element by the color of flame it produces.
Ex: copper produces
c:speed of light (3.00 108 m/s)
:wavelength (m, nm, etc.)
= 3.00 108 m/s
4.34 10-7 m
= 434 nm = 4.34 10-7 m
c = 3.00 108 m/s
= 6.91 1014 Hz
E:energy (J, joules)
h:Planck’s constant (6.6262 10-34 J·s)
E = h
E = ?
= 4.57 1014 Hz
h =6.6262 10-34 J·s
E = h
E = (6.6262 10-34 J·s)(4.57 1014 Hz)
E = 3.03 10-19 J