Answer:
4
Explanation:
The Balmer series refers to to a series of spectral emission lines of the hydrogen atom that occurs when an electron moves from higher energy levels to the energy level of n= 2.
Hence;
λ = 486.3 * 10^-9 m
RH = 1.097 * 10^7 m-1
nf = 2
ni = ?
Using the formula;
1/λ = RH (1/nf^2 - 1/ni^2)
1/486.3 * 10^-9 = 1.097 * 10^7 (1/4 - 1/ni^2)
2.06 * 10^6/1.097 * 10^7 = (1/4 - 1/ni^2)
0.188 = 1/4 - 1/ni^2
1/ni^2 = 1/4 - 0.188
1/ni^2 = 0.25 - 0.188
1/ni^2 = 0.062
ni^2 = 16
ni = 4