In this worksheet, we will practice using the Planck constant and speed of light to convert between energies and wavelengths of electromagnetic waves.

**Q1: **

Atomic emission spectra of the hydrogen atom show a red line at a wavelength of 656 nm. Given that the speed of light is and Planck’s constant is , what is the energy possessed by one photon at this wavelength?

- A
- B
- C
- D

**Q2: **

The atomic emission spectrum of the hydrogen atom shows a violet line at a wavelength of 434.0 nm. Calculate the energy of one photon at this wavelength. Use a value of for the speed of light and for Planck’s constant.

- A
- B
- C
- D

**Q3: **

Heated thallium ions emit photons with an energy of J.

Calculate the wavelength of the emitted photons.

Calculate the energy per mole of emitted photons.

**Q4: **

Heated barium ions emit photons with an energy of 2.722 eV.

Calculate the wavelength of the emitted photons.

Calculate the energy per mole of emitted photons.

**Q5: **

In a flame test, bismuth atoms emit photons with an energy of 4.042 eV.

Calculate the wavelength of the emitted photons.

Calculate the energy per mole of emitted photons.

**Q6: **

Mercury atoms in a high-pressure lamp emit photons with an energy of 6.705 eV.

Calculate the wavelength of the emitted photons.

Calculate the energy per mole of emitted photons.

**Q7: **

The atomic emission spectrum of nitrogen contains a strong line corresponding to photons with an energy of J.

Calculate the wavelength of the emitted photons.

Calculate the energy per mole of emitted photons.

**Q8: **

How many infrared photons with a wavelength of m must be absorbed by 190 g of water to increase the temperature from 25.0 to ? The specific heat capacity of water is 4.184 J/g⋅K.

- A 90.9 mmol
- B 82.4 mmol
- C 83.0 mmol
- D 86.4 mmol
- E 77.7 mmol