If the frequency of light is known to be 9.45 × 10¹⁴hz, what is the wavelength in meters?

A. 3.17 × 10^-7 m
Correct! Rearrange the formula c = λf to solve for wavelength, λ = c/f.

B. 3.15 × 10⁶ m
Incorrect. This is λ = f/c which is incorrect rearrangement of the formula.

C. 2.85 × 10²³ m
Incorrect. This is λ = cf which is incorrect rearrangement of the formula.

D. 6.26 × 10^-19 m
Incorrect. This is λ = hf which is an incorrect formula.

What is the energy of a photon of light whose frequency is 7.85x10¹⁵ Hz?

A. 2.53 × 10^-41 J
Incorrect. This is an incorrect use of the formula E_photon = hc/λ.

B. 3.82 × 10^-8 J
Incorrect. This is an incorrect use of the formula λ = c/f, the problem is asking for energy not wavelength.

C. 5.20 × 10^-18 J
Correct! Use the formula E_photon = hf to solve for energy.

D. 2.36 × 10²⁴ J
Incorrect. This is an incorrect use of the formula c =λf.

If light has a wavelength of 5.50 × 10^-7 m, what is the energy of one photon of this light?

A. 5.45 × 10¹⁴ J
Incorrect. This is an incorrect use of the formula c =λf which solves for frequency, not energy.

B. 3.61 × 10^-19 J
Correct! Using the formula E_photon = hc/λ, plug the numbers in and calculate.

C. 1.09 × 10^-31 J
Incorrect. This is an incorrect use of the formula E_photon = hc/λ.

D. 3.64 × 10^-40 J
Incorrct. This is an incorrect use of the formula E_photon = hf, you are given the wavelength not frequency.