Electromagnetic Waves EQ What is an electromagnetic wave

Electromagnetic Waves EQ: What is an electromagnetic wave and its properties?

Vocabulary • Electromagnetic waves- shower of transverse waves consisting of changing electric and magnetic fields • EX: Radio, infrared, visible light, UV, Xrays, gamma waves

Water & Sound Waves • Transfer energy from one place to another. • Need a medium to move.

Waves… a review Water and Sound waves: • Transfer energy. • Need a medium to move.

ELECTROMAGNETIC WAVES • TRANSVERSE WAVES! • 2 properties: electrical and magnetic!

Electromagnetic (EM) waves consist of vibrating electric and magnetic fields. • • EM waves travel at the speed of light (300, 000 km per second) through a vacuum. transfer energy and can interact with matter.

ELECTRIC FIELD • A region where charged particles are moving. • Found wherever there is an electric charge. • Surrounded by a magnetic field.

Vocabulary EM Radiation – energy that is transferred by electromagnetic waves – Does not need a medium to travel Speed of electromagnetic waves all waves travel at the same speed in a vacuum, like space, EMW travel at 300, 000 km per second When EMW travel through our atmosphere, they travel more slowly but they are still the fastest waves Takes 8 minutes for sunlight to reach earth!

Light – Waves or Particles? • Ordinary beam has waves that vibrate in all directions. • Polarizing filters allow only some waves to pass, so it is called polarized light.

Stream of Particles Light is also made of tiny particles called protons. When light shines on some substances, it causes tiny particles, called electrons, to move. When this happens an electric current starts to flow. This is called photoelectric effect. (PHOTONS!)

Class Work and Homework • Fill In – What did I learn – Confused – Say – Read pages O 76 – O 79, Questions 1 -4, page 79