Question

Use the Bohr model to find the second longest wavelength of light in the Paschen series for a doubly-ionized Li atom (Z = 3). Recall that the Paschen series corresponds to transitions to the second excited-state (n = 3 level).

a) 13.5 nm

b) 117 nm

c) 143 nm

d) 41.1 nm

e) 209 nm

Answer 1

Thankyou.

Answer, Given for li atom, Z=3 Let the wavelength of light in the paschen Series is = X Then we know Bohr's theory, =Rk ( 11 ) st Here, ne - 3 for paschen series. and for second largest wavelength, ni = 5 and R = Rydberg Constant = 1.09625 X107 m) Hence, - = RĂ ( the -> == 1.09625x10x3 5) 34 5 2016000 => a=1.42538107 g = 142.53 X10 a = 142.53 nm a ~ 143 nm Answer: c) 143 nm