SCH 4U
c=λxυ
E = hυ
RYDBERG AND PLANCK EQUATIONS – WORKSHEET
the wave
equaton
Planck’s
equation
Due Date: ______________________________
 1
1
1
= RH 

n 2 n 2

i
 f




where RH = 1.10 x 107/m
Rydberg equation
1. Find the energy in kJ for an X-ray photon with a frequency of 2.4 × 1018 s –1.
2. In general, the human eye cannot detect photons of frequency – greater than 789 THz
(THz = terrahertz)
– less than than 429 THz
a) Find the maximum photon energy necessary to stimulate receptors in the eye.
b) What wavelength does this maximum photon energy correspond to?
c) What is the wavelength of the minimum photon energy detectable?
3. Cell phone signals can operate at different frequencies.
One of the highest frequencies has a wavelength of 0.125 m.
a) What is the energy of this frequency?
b) Consider your answer from 3a and the values calculated in #2.
How many times greater is the minimum energy detectable light compared to the maximum
energy of the strongest cell phone signal?
4. What is the wavelength, in nm, of a light photon with an energy content of 535 kJ/mol?
In what part of the electromagnetic spectrum do you find this light?
5. Assume the maximum number of energy levels an atom can have is 7.
a) What evidence does the (current) periodic table offer to support this assumption?
b) Based on this assumption, what (approximate) energy would an electron need to absorb
to escape an atom?
6. Use algebraic substitution to combine the wave equation and the Planck equation to
determine the energy of photons of this blue-violet light in a single combined calculation.