Calculate the wave number and wave length of `H_(beta)` line in the Balmer series of hydrogen emission spectrum.

Explanation

For `H_(beta)` line in the Balmer series `n_(1) = 2 and n_(2) = 4`
`bar(upsilon)=109677((1)/(2^(2))-(1)/(4^(2)))=20564.5cm^(-1)`
`lambda=(1)/(bar(upsilon))=(1)/(20564.5)=4.867xx10^(-5)cm`
Wave number of `H_(beta)` line `=2.0564xx10^(4)cm^(-1)`
Wave length of `H_(beta)` line `=4867Å`