TOPIC: Electrons as WAVES: Quantum Model of ATOMDate: _October 31, 2016

Essential Question: _What are the characteristics of a wave? How does the ELECTRON behave as a wave and as a PARTICLE?

  • Electrons could act as both ____PARTICLE______and _____WAVES______– Louis de Broglie (French physicist in 1924)

What is a WAVE?

A wave is a transfer of ___ENERGY______from one point to another via a traveling __Disturbance______

A wave is characterized by it’s : __wavelength______; ___frequency______; and ___amplitude______

What is a WAVELENGTH?
  • __DISTANCE______from successive crest to ___crest______or trough to ___trough______
/
What is a FREQUENCY?
  • __number______of __waves______passing by per second
  • Measured in ___HERTZ______(Hz) defined to be one cycle per sec
/
IWhat is an AMPLITUDE?height of the wave
  • Maximum ___DISPLACEMENT______of the wave
  • The amplitude will have different units depending on the type of wave
  • In a sketch of the wave, it is the distance from the __middle______of the wave to the ___peak______
/

LIGHT: What is it?

Light Energy

Atoms – 1.) As atoms ____absorbs______energy, electrons __jump______out to a ___higher______energy level. Electrons release _____light______when falling ___down______to the ____lower______energy level.

___PHOTONS______- bundles/packets of energy released when the electrons fall.

__light______: Stream of Photons

Electromagnetic Waves

Speed in Vacuum - 300,000 km/sec or 186,000 mi/sec

Speed in Other Materials - Slower in Air, Water, Glass

QUESTIONS: (3 level 1)/ (2 level 2) (1 level 3) ______

Electromagnetic Spectrum

VISIBLE LIGHT
/ Starting from left:
RED – longest wavelength; Lowest frequency; lowest Energy
Orange-
Yellow -
Green –
Blue – short wavelength; high frequency; high energy
Indigo
Violet- shortest wavelength; highest frequency; highest energy

SUMMARY:______

The electromagnetic (EM) spectrum is the range of all types of EM radiation.

Electromagnetic radiation is a type of energy that is commonly known as light.

Electromagnetic energy is a term used to describe all the different kinds of energies released into space by stars such as the Sun.

Frequency  number of waves per time

Gamma rays Have the smallest wavelengths and the most energy of any wave in the EM spectrum. They are produced by the hottest and most energetic objects in the universe such as supernova explosions. On earth, gamma waves are generated by nuclear explosions, lightning and radioactive decay.

Infrared waves  what most people encounter everyday as “HEAT”

It is one of the three ways heat is transferred from one place to another, the other two being convection and conduction.

Microwaves  type of EM radiation and is used in communication, radar, and perhaps best known by most people, cooking. It is found between radio and Infrared waves.

Electromagnetic Spectrum and Light

1.)Electromagnetic spectrum is the range of all types of Electromagnetic (EM) radiation.

2.)Radiation  is energy that travels and spreads out as it goes.

Ex. The visible light that comes from a lamp; radio waves that come from a radio station

3.)A.) Visible light what our eyes can detect

Ex. Fireflies, light bulbs, and stars all emit visible light

B.) Microwaves this type of radiation will cook your popcorn in few minutes and also used by astronomers to learn about the structure of nearby galaxies.

C.)Gamma rays most harmful radiation yet doctors use gamma-ray imaging to see inside your body. The biggest generator of all is the UNIVERSE (supernova explosion).

D.)Infrared – “body heat”. Night vision goggles pick up the infrared light emitted by our skin and objects with heat. In space, infrared light helps us map the dust between stars

E.)Ultraviolet radiation is emitted by the sun and is the reason skin tans and burns. “Hot” objects in space emit UV radiation as well.

F.)X-rays A dentist uses X-rays to image your teeth, and airport security uses them to see through your bag. Hot gases in the universe also emit X-rays

G.)Radio waves your radio captures radio waves emitted by radio stations, bringing your favorite tunes. Radio waves are also emitted by stars and gases in space.