Day 5 12-9

2. High frequency = _____ energy and ______ wavelength

HighShort

h

a

1. Amplitude affects __________.

2. Shorter wavelengths = ______ frequencies

higher

brightness

Quantum Theory

What did scientists observe that led them to view light as quantized?

Quantum Theory

How is energy related to frequency?

Frequency to wavelength?

And so energy to wavelength?

Quantum Theory

2. Who demonstrated photons can move electrons?

ComptonAHHHH!

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

Periods 3 & 6

The relationship between frequency , wavelength (), and color to the energy of light: ,

Color: red = low E, violet = high E

E : many photon punchesE: big gaps between consecutive photons.

Color: red = low E, violet = high E

each color has its own energy

color = type of light

The Effects of Different Photons:Microwaves: can’t feel

Infrared: feel with skin, warms or burns.

Visible light: see with eyes, heats when absorbed.

Ultraviolet: can’t feel or see, affects cells – freckles, tan, burn, cataracts.

X-rays: can’t feel or see, pass through body, but absorbed by bones and dense matter.Gamma rays: can’t see or feel, affects cells, causes mutations in cells and molecules.

The Effects of Different Photons:Ultraviolet: can’t feel or see, affects cells – freckles, tan, burn, cataracts.

Day 6 12-12

2. Low energy = _____ fequency and ______ wavelength

LowLong

h

a

1. Amplitude affects __________.

2. Shorter wavelengths = ______ frequencies

higher

brightness

Quantum Theory

Radiant Energy =

The dual nature of light?

Sun or electromagnetic radiation

Light can act as a particle OR a wave

Quick TalkRadiant energy

Wavelength

Compton

Quantized

Bohr

Electron

Light

Dual nature

Proton

Amplitude

Electromagnetic radiation

Neils BohrTried to explain

why each element has its own unique (bright) line (bright) line spectrumspectrum. He studied HH.

Using previous discoveries- Bohr hypothesized that an atom’s electrons are located in specific energy levelsspecific energy levels. Each energy level, aka orbitorbit or shellshell is a set distance from the atom’s nucleusnucleus. …

… Electrons jumpjump or fallfall from one energy level to another, while simultaneously gaining or losing energyenergy. Electrons are not permitted to stop betweenbetween energy levels.

Neils Bohr… Each energy

level, aka orbitorbit or shellshell. Is a set distance from the atom’s nucleusnucleus. …

Bohr’s Hypothesis•In the line spectrum of an In the line spectrum of an atom, Bohr saw specific atom, Bohr saw specific colors.colors.

•Each specific color has a Each specific color has a specific energy.specific energy.

•That specific amount of That specific amount of energy is related to a energy is related to a specific specific distance from the distance from the nucleus.nucleus.

Review section 5.3 AND complete #s 19, 20, 22, and 23

on page 148