Electron's Energy After Absorbing A Photon

[Kennedy111]

Homework Statement

An electron in the 3rd stationary state around a hydrogen atom has an energy value of -1.512 eV. What will the electron's energy be if the hydrogen atom absorbs a photon with a wavelength of 1090 nm?

E = -1.512 eV

Homework Equations

Ephoton = hc/λ

The Attempt at a Solution

I'm unsure if my formula was the correct one to use...

E photon = hc/λ
= (6.63 x 10^-34 J*s)(3.00 x 10^8 m/s) / (1090 x 10^-9 m)
= 1.82477064 x 10^-19 J
= 1.140481651 eV

ΔE = Ef - Ei
Ef = ΔE + Ei
= (1.140481651 eV) + (-1.512 eV)
= -0.371518349 eV

The electron's energy will be about -0.3715 eV

I am really just unsure of my process and therefore my answer, so I would just like a second opinion. Thank you!

 

[ehild]

Your method is correct, but you gave the result with four significant digits while calculating with values of h and c accurate to three digits. As the initial energy and wavelength were given with four significant digits, use more accurate values for c and h.

ehild