Transcript Slide 1

Wavelength – λ – distance between successive
points on a wave (crest to crest)
Amplitude – vertical distance fro the midline of a
wave to the peak or trough
Frequency - ν – number of waves that pass a
point in 1 second Hz = cycles per second
• Speed of a wave u = λ ν
Problem page 248
Calculate the frequency (in Hz) of a wave
whose speed and wavelength are 713 m/s
and 1.14 m, respectively.
Electromagnetic Spectra
Electromagnetic Spectra
Electromagnetic Spectra
Electromagnetic Spectra
• Electromagnetic waves Travel at the
speed of light = 3.00 x 108 m/s or
186,000 mi/s
•ν=c/λ
Problem page 249
What is the wavelength (in meters) of an
electromagnetic wave whose frequency is
3.64 x 107 Hz?
Planck’s quantum theory
Quantum – the smallest quantity of energy
that can be emitted or absorbed in the
form of electromagnetic radiation.
• E = hν
• h = planck’s constant = 6.63 x 10 -34 J s
Planck’s quantum theory
• Energy is always emitted in multiples of
hν… 2 hν…. 3 hν
Photoelectric effect
Problem page 252
• The energy of a photon is 5.87 x 10-20
What is its wavelength in nanometers?