Answer:
10.9 * 10^-7 m
Step-by-step explanation:
We know that the Rydberg constant (R) is – 13.6 eV = -2.18 * 10^-18 J
ΔE= -R(1/nf - 1/ni)
Where;
nf = final state
ni= initial state
ΔE= -2.18 * 10^-18(1/3 - 1/4)
ΔE= -2.18 * 10^-18(1/12)
ΔE= -1.81 * 10^-19 J
From;
ΔE=hc/λ
h = plank's constant = 6.6 * 10^-34 Js
c = 3 * 10^8 ms-1
λ = ?
λ = hc/ΔE
λ = 6.6 * 10^-34 * 3 * 10^8/ 1.81 * 10^-19
λ = 10.9 * 10^-7 m