Student will learn:
Relationship between light & electrons
What produces color
Electromagnetic Spectrum Readings
Neils Bohr Model of Hydrogen Readings
Atomic theory = Dalton
Electron discovery = JJ Thomson
Electron charge = Millikan
Nucleus discovery = Rutherford
Neutron = Chadwick
Neils Bohr
What keeps the negative
electrons from falling toward
the positive nucleus?
Neils Bohr
What keeps the negative electrons from falling
toward the positive nucleus?
The emission of light is
related to the behavior
of the electrons.
Light as a Wave
Light as a stream of photons
Tiny little packets of quantum energy
Light: travels in waves, made up of photons
Photons : zero mass, contain a quantum energy
Glasses
Light = electromagnetic radiation
energy from light affects electrons
• Ground State: lowest energy state of an atom.
• Excited State: an atom has absorbed
energy higher than ground state.
• Electromagnetic radiation: The energy
given off when an excited atom
returns to its ground state.
“production of colored light / luster of a metal”
Absorption / Emission of Photon
An excited atom returns to a lower energy level.
Excited State
Photon
emitted
Ground State
The color of the photon emitted depends on
the energy change that produces it.
Excited state two
Excited state one
Each photon emitted corresponds to a
particular energy change.
4 excited states… each
one may emit a different
color
? What is the principal number of electrons that produces the 1094
infared wavelength?
? A Red light is produced when the electrons fall back from energy
level 3 to energy level_________.
? A Violet light is produced when the electrons fall back from energy
level __________ to energy level_________.
? For hydrogen to produce a UV wavelength
the electron must fall back from what to
what?
Student will learn:
Relationship between light & electrons
What produces color
Electromagnetic Spectrum Readings
Neils Bohr Model of Hydrogen Readings