The shortest wavelength which can be obtained in hydrogen spectrum `(R=10 ^(7) m^(-1))`

Options

A. 1000 Å
B. 8000 Å
C. 1300 Å
D. 2100 Å

Answer

A

Explanation

The wavelemgth can be given as
`" "(1)/(lambda)=Z^(2)R((1)/(n_(1)^(2))-(1)/(n_(2)^(2)))`
For `lambda` to the shortest `((1)/(n_(1)^(2))-(1)/(n_(2)^(2)))` should be maximum
So, `" " n_(2)=oo and n_(1)=1`
Now, from Eq. (i) we get
`(1)/(lambda)=R((1)/(1))rArrlambda=(1)/(R)=(1)/(10^(7))m~~ 1000Å`