Calculate the wave number and wave length of `H_(alpha)` line in Brackett series of H-emission spectrum

Explanation

For `H_(alpha)` line in Brackett series
`n_(1) = 4, n_(2) = 5`
`bar(v) = R [(1)/(n_(1))-(1)/(n_(2))] = 109677 [(1)/(4^(2))-(1)/(5^(2))] = 2467.7325 cm^(-1)`
`lambda = (1)/(v) = 4.0 xx 10^(-4)cm`