1. What does it mean if something is quantized? Day

Continuous: VS. Quantized: Height by step or rung Height on slide or ramp

Continuous: VS. Quantized:

Radiant Energy travels through space is energy that travels through space. light Is also known as light and electromagnetic radiation electromagnetic radiation. Major source is… THE SUN

Radiant Energy… Sun’s radiant energy is the result of nuclear fusion. Nuclear fusion – light nuclei combine to form heavier nuclei Fission vs. fusion?

The dual nature of light Particle??? Wave??? The dual nature – light can be viewed as a wave (continuous) OR a stream of extremely tiny, fast- moving particles (quantized)

The dual nature of light Particle??? Wave??? - Wave (continuous) as it travels through space - Particle (quantized) as it interacts with matter

Electromagnetic Spectrum ordered sequence light electromagnetic radiation The ordered sequence of all types of light or electromagnetic radiation.

The part of the electromagnetic spectrum that humans can see is called the … radio, micro, radar, IR, vis. Electromagnetic Spectrum vis., UV, X-ray, gamma, cosmic Low, low & Long! High, high & short!

Violet- High energy, bends more, inside of rainbow, 400 nm R O Y G B I V Red- Low energy, bends less, outside of rainbow, 700 nm

Sir Isaac Newton …in the 1670’s, diffracted light with a prism and… Concluded that each color of light has a unique wavelength… energy

Electromagnetic Spectrum h a

amplitude (a) - affects brightness, half the height Frequency (ν) = number of crests passing a point in a period of time h = height, from crest to trough speed (c) = distance per unit time wavelength (λ) = crest to crest

λ = c/ν wavelength speed of light frequency

Radiant Acrostic RADIANTRADIANT

DEFINE: energy level AND atomic orbital AND Read section 5.1 AND answer questions 1, 2, 4, and 5 on page definitions and 4 questions Day

1. Amplitude affects __________. 2. Longer wavelengths = ______ frequencies lower brightness Day

How do we know that atomic energies are quantized? Day

Note page 2: If a light wave has a wavelength (λ) of 3.0 * m, what is its frequency? wavelength speed of light frequency C = 3 * 10 8 m/s 1.0 * Hz

Radiant Energy… The dual nature of light?

Quantum Theory Beginning of 20 th century – wave model is almost universally accepted. Problem = electromagnetic radiation emitted from hot objects

Can all light be described as continuous The energy of waves is continuous, or unbroken… When we look at an object as it is heated, what do we see? Quantum Theory … - quanta

Stop and summarize

Each color has its own energy And the energy changes with heating Quantum Theory … - quanta

Max Planck energy - related the frequency of light to its energy with the following: E = h Energyh=Planck’s const. E=Energy, h=Planck’s const. specific amounts His idea was that energy is absorbed and released in specific amounts. Quantum Theory 6.626e-34 J*s

specific amounts quantum quanta atoms His idea was that energy is absorbed and released in specific amounts. He called one piece, package, or bundle of energy one quantum. Bundles of energy were called quanta. He applied his quanta ideas to energy changes in atoms: Quantum Theory

atoms quantized continuous (wave-like) He applied his quanta ideas to energy changes in atoms: The energy of atoms is quantized. Formerly, scientists had thought that all energy was continuous (wave-like). Quantum Theory

Democritus’ atom Quantized Matter:Energy:Plank

Continuous: VS. Quantized: Height by step or rung Height on slide or ramp

Continuous: VS. Quantized: Ice cream scoops Soft-serve ice cream

Quantized: VS. Continuous: escalator stairs

Continuous: VS. Quantized: Cheese singles Cheese block

Quantum Theory Come up with your own: Continuous VS. Quantized: AND put it in your notes!

Albert Einstein - Imagined that light energy traveled in bundles - photons. 18 years later, Arthur Compton experimentally demonstrated that light is comprised of tiny particles, or photons, Quantum Theory

TODAY - Planck’s term quantum and Einstein’s term photon are used interchangeably. demonstrated that light is comprised of tiny particles, or photons, that can collide with electrons and cause them to move. Quantum Theory

TODAY - Planck’s term quantum and Einstein’s term photon are used interchangeably. Scientists also believe that light has properties of both waves and particles. Quantum Theory … - Dual nature of light

h a

radio, _______, radar, IR, vis. vis., ___, X-ray, gamma, cosmic _________ & Long ________ & Short! λ = c/ν

Violet- ______ energy, bends more, inside of rainbow, 400 nm R O Y G B I V Red- _____ energy, bends less, outside of rainbow, 700 nm