The wavelength of the first line of Balmer series is `6563 Å`. The Rydbergs constant fro hydrogen is about

Options

A. `1.09 xx 10^(7)` per `m`
B. `1.09 xx 10^(8)` per `m`
C. `1.09 xx 10^(9)` per `m`
D. `1.09 xx 10^(5)` per `m`

Answer

A

Explanation

`(1)/(lambda) = R [(1)/(4) - (1)/(9)] = (5R)/(36)`
`:. R = (36)/(5 lambda) = (36)/(5 xx 6563 xx 10^(-10)) = 1.09 xx 10^(7) m^(-1)`