Answer:
Wavelength = 1.362 x 10-7 m
Explanation:
ΔE = hc/λ
λ = hc/ΔE
hc = (6.626 x 10-34 Js)(3 x 108 m/s) = 1.9878 x 10-25 J m
λ = (1.9878 x 10-25) / ΔE, with ΔΕ in J, λ in meters
from E1 to E4
ΔE = E4 - E1 = [(-1.91 × 10-19) - (-1.65 × 10-18)] J = 1.459 x 10-18 J
Inserting the value of ΔΕ into the equationabove, we have;
λ = (1.9878 x 10-25) / (1.459 x 10-18) m = 1.362 x 10-7 m