Finding Frequency?

Question

Part 1

You have 0.100 mol of H atoms in the ground state. How much energy is required to transition all of the atoms from the ground state to n=5?

1.26×105 J

Part 2

What is the frequency of the light required to make this transition?

= ____ Hz

I found 1.902e38 Hz and it said that it was incorrect.

Answer 1

∆E = 2.179x10^-18 J (1/n₁² - 1/n₂²) = 2.179x10^-18 J (1/1 - 1/25)

∆E = 2.179x10^-18 J x 0.96

∆E = 2.09x10^-18 J / electron x 6.02x10²³ electrons/mol x 0.1 mol = 1.26x10⁵ J

E = hν

ν = E/h = 2.09x10^-18 J/6.626x10^-34 Jsec

ν = 3.15x10¹⁵ s^-1 = 3.15x10¹⁵ Hz