Verified answer

E = Rh ( 1/n^2 - 1/n2^2) = 2.18x10^-18 J ( 1/36 - 1/4) = 4.84x10^-19 J

(Ignore the negative sign, energy is absolute value)

E = h v

c = λ v

v = c / λ

E = h c / λ

h, planck's constant

c, speed of light

λ = h c / E = 6.626x10^-34 J s x 3.00x10^8 m/s / 4.84x10^-19 J = 4.1x10^-7 m

1 nm = 1.0x10^-9 m

Divide by 1.0x10^-9 to convert from m to nm

4.1x10^-7 m x ( 1 nm / 1.0x10^-9 m ) = 410 nm