Q.
The shortest wavelength of the Brackett series of a hydrogen like atom (atomic number =Z ) is the same as the shortest wavelength of the Balmer series of hydrogen atom. The value of Z is
Shortest wavelength of Brackett series corresponds to the transition of electron between n1=4 and n2=∈fty and the shortest wavelength of Balmer series corresponds to the transition of electron between n1=2 and n2=∈fty , So, (z2)(1613.6)=(413.6) ∴Z2=4
or Z=2