Question

Let v₁ and v₃ be the frequency for series limit of Balmer and Paschen series respectively. If the frequency of first line of Balmer series is v₂ then, relation between v₁ and v₂ and v₃ is ____________.

Options

• v₁ + v₃ = v₂

• v₁ - v₂ = v₃

• v₁ + v₂ = v₃

• v₂ - v₁ = v₃

Answer 1

Let v₁ and v₃ be the frequency for series limit of Balmer and Paschen series respectively. If the frequency of first line of Balmer sereis is v₂ then, relation between v₁ and v₂ and v₃ is v₁ - v₂ = v₃.

Explanation:

Series limit of Lyman series

v₁ = CR(1)

Series limit of Balmer series

`"v"_3 = "CR"/4`

First line of Lyman series

`"v"_2 = "CR" (1 - 1/4) = 3/4 "CR"`

`therefore "v"_1 + "v"_3 = "v"_1` or  `"v"_1 - "v"_2 = "v"_3`