Multiple Choice
What is the source of energy that provides the boost for electrons during photosynthesis?
9. Quantum Mechanics
The Energy of Light
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How much energy (in kJ) do 4.50 moles of photons contain at a wavelength of 705 nm?
A
2.58 x 102 kJ
B
7.64 x 102 kJ
C
8.45 x 102 kJ
D
5.89 x 102 kJ
Verified step by step guidance1
First, understand that the energy of a photon can be calculated using the equation: , where is Planck's constant (), is the speed of light (), and is the wavelength in meters.
Convert the wavelength from nanometers to meters. Since 1 nm = 1 × 10-9 m, the wavelength of 705 nm is .
Substitute the values of , , and into the energy equation to find the energy of a single photon: .
Calculate the energy for 4.50 moles of photons. Since 1 mole contains photons (Avogadro's number), multiply the energy of one photon by .
Convert the total energy from joules to kilojoules by dividing by 1000, as 1 kJ = 1000 J. This will give you the energy in kJ for 4.50 moles of photons.
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