1. Light Practice Problems
Ms. DiOrio

2. Equations
On Equation Sheet
NOT on Equation Sheet
Planck’s Equation: 𝐸=ℎ𝜈 Wave Equation: 𝑐= 𝜆𝜈 Beer’s Law: A = abc E = energy 𝜈 = frequency 𝜆 = wavelength Planck’s Constant: h = x Js Speed of light: c = 3 x 108 m/s
𝐸= ℎ𝑐 𝜆 𝐸=𝑛ℎ𝜈 De Broglie Equation: λ= ℎ 𝑚𝑣 Bohr Equation: ∆𝐸=−2.178𝑥 10 −18 ( 1 𝑛 𝑓𝑖𝑛𝑎𝑙 2 − 1 𝑛 𝑖𝑛𝑖𝑡𝑖𝑎𝑙 2 )

3. What is the wavelength of a FM radio transmission at 88.9 MHz?

4. What is the frequency of light with a wavelength of 660 nm?

5. Ultraviolet radiation has a frequency of 6. 8 × 1015 s-1
Ultraviolet radiation has a frequency of 6.8 × 1015 s-1. Calculate the energy, in joules, of the photon.

6. A sodium vapor lamp emits light photons with a wavelength of 5
A sodium vapor lamp emits light photons with a wavelength of 5.89 × 10-7 m. What is the energy of these photons?

7. A ruby laser produces red light that has a wavelength of 500 nm
A ruby laser produces red light that has a wavelength of 500 nm. Calculate its energy in joules.

8. What is the frequency of UV light that has an energy of 2.39 × 10-18 J?

9. Determine the de Broglie wavelength (in nm) associated with a neutron traveling at a speed of 5.0 x 103 m/s. The mass of a neutron is 1.67 x 10–24 g.

10. What is the wavelength of an electron moving at 5
What is the wavelength of an electron moving at 5.31 x 106 m/s if an electron has a mass of 9.11 x kg?

11. An atom of helium has a de Broglie wavelength of 4. 30 x 10¯12 m
An atom of helium has a de Broglie wavelength of 4.30 x 10¯12 m. What is its velocity?

12. Calculate the wavelength of the radiation emitted by a hydrogen atom when an electron falls from the n=3 to the n=2 orbital in the Bohr model.

13. What is the ionization energy of an electron in the n=3 shell of a hydrogen atom?

14. What is the molar absorptivity of the following compound as measured in a 1 cm cuvette? Concentration: 25uM Absorption:

15. What is the concentration of the following compound as measured in a 1 cm cuvette: Molar absorptivity: 4525 M-1cm-1 Absorption:

16. A student wishes to analyze the concentration of an unidentified yellow solution. What wavelength should be used to measure absorption?