The wavelength of the first member of Lyman series is `1216 Å`. Calculate the wavelength of second member of Balmer series.

Explanation

`(1)/(lamda)=R((1)/(n_(1)^(2))-(1)/(n_(2)^(2)))`
For `1^(st)` member of Lyman series, `lamda=1216,`
`n_(1)=1, n_(2)=2`
`(1)/(1216)=R((1)/(1^(2))-(1)/(2^(2)))`
`rArr (1)/(1216)=(3R)/(4)" "rarr(1)`
For `2^(nd)` member of Balmer series,
`(1)/(lamda^(1))=R((1)/(2^(2))-(1)/(4^(2)))" "[because n_(1)=2, n_(2)=4]`
`(1)/(lamda_(1))=(3R)/(16)" "rarr(2)`
`((1))/((2))rArr(lamda^(1))/(1216)=(3R)/(4)xx(16)/(3R)`
`therefore lamda^(1)=1216xx4=4864 Å.`