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 BohrWhat 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 stream of photons

Tiny little packets of quantum energy

Light as a Wave

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.

Ground State

Excited State

Photon emitted

The color of the photon emitted depends on the energy change that produces it.

Excited state one

Excited state two

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