Highlights on TEST!!!!
Citations in report AIP style. (AMERICAN INSTITUTE OF PHYSICS STYLE)
1 nanometer = 1nm = 1m = 1x10 m = 10 m 1 x 10-9 9
Ά red00nm = 700 x 10 m = 7 x 10 m
Ά violet400nm = 400 x 10 m = 4 x 10 m -4
Ά green 700+400 /2 = 550nm
Visible colours: ROY G BIV
Photons: bundles of energy light as a particle
Whitelights consist of all colours of the rainbow. But human brains cannot see them so we see white.
When white light passes through a prism the colours are visible separately
Ultraviolet, Xrays and gamma rays are the short wavelengths and are dangerous
Frequency = f
= number of wave peaks passing a given point each second.
= number of waves/second
= complete cycles/second
Unit = Hz, hertz. Electricity is 120 cycles per second or 120Hz
Frequency = speed of light / wavelength ( c/Ά)
Fred= 3 x 10 m/s / 700 x 10 m. Use exponential button in calculator. Try violet, green for HW.
PLANCK CURVE Get star in telescope.
Sequence of coloured filters at eyepiece end of telescope
PEAK = 550nm
V I B G Y O R
PLANK CURVE is a graph of filter colour
Calculate temperature of a object via WIEN Formula: T = (0.0029 m.K) / Ά dom
WIEN FORUMLA CALCULATION: T = (0.0029 m.K) / 550 x 10 m
T = 5272.7 ~ 5300K
Surface temperature of the sun is ~ 5800K
Absolute zero = -273 celcius. It is when
ENERGY OF LIGHT
Formula for energy: E = hf. f= frequency h = Planks of constant E = energy in joules
Ered(6.625 x 10 j.s) (4.3 x 10 cycles/s)
Ered= 2.85 x 10 J9
Note: shorter wavelengths higher frequencies and energies.
As wavelength goes down. Frequency and Energy go UP.
THE BOHR MODEL OF THE HYDROGEN ATOM Proton