For which of the following hydrogen-like species, the wavelength of radiation emitted due to electron shifts from n = 2 to n= 1, has a maximum value?H H e + L i 2 + B e 3 +

Options

A. H
B. `He^(+)`
C. `Li^(2+)`
D. `Be^(3+)`

Answer

A

Explanation

`(1)/(lamda) = Z^(2) R_(oo) ((1)/(n_(1)^(2))-(1)/(n_(2)^(2)))=Z^(2)R_(oo) ((1)/(1^(2))-(1)/(2^(2)))=(3)/(4) Z^(2) R_(oo)," Hence, "lamda =(4)/(3Z^(2) R_(oo))`
Leser the value of Z (i.e. hydrogen atom) larger the wavelength.