Answer to Question #84819 in Physical Chemistry for adarsh

Question

For the first two lines of Paschen series, identify the value of n1 and n2.
Calculate the wave number values for these lines.

Answer 1

In Paschen series the elctrons fall back to n₁ = 3.

First line n₁ = 3 , n₂= 4

We should use Rydberg equation to calculate wave number value:

ν = R*(1/n₁² - 1/ n₂²)

v = 1.09678*10⁷ (1/3² - 1/4²) = 5.331*10⁵ m^-1

Second line n₁ = 3 , n₂ = 5

v = R*(1/n₁² - 1/ n₂²)

v = 1.09678*10⁷ (1/3² - 1/5²) = 7.799*10⁵ m^-1