what is the energy of an photon having a wavelength of 4.50 mm?

Question

I used e=hv equation. I converted 4.50 mm to m then to nm which I got 4500000 nm then multiply it by the h constant. I did not get any of the answer choices.

a.7.82 x 10^-33 J

b. 1.68 x 10^-26 J

c. 4.42 x 10 ^-23 J

d. 7.82 x 10 ^-42 J

Answer 1

But v isn't the wavelength, it's the frequency. So, you can't use E = hv for this. But rather, since given the wavelength of 4.50 mm, we can use E = hc/λ

E = ?

h = 6.626x10^-34 Jsec

c = 3x10⁸ m / sec

λ = 4.50 mm x 1 m / 1x10³ mm = 4.5x10^-3 m

E = (6.626x10^-34 Jsec)(3x10⁸ m / sec) / 4.5x10^-3 m

E = 4.42x10^-23 J (ANSWER C)