Which transition in the hydrogen spectrum would have the sam... | Chemistry | SolveeIt | Solveeit

Today, August 18

Question

Which transition in the hydrogen spectrum would have the same wavelength as the Balmer type transition from $n =4$ to $n =2$ of $He ^{+}$ spectrum

A

$n =1$ to $n =3$

B

$n =1$ to $n =2$

C

$n =2$ to $n =1$

D

$n =3$ to $n =4$

Answer

$n =2$ to $n =1$

Explanation

Solution

He+ion :
λ(H)1=R(1)2[n121−n221]
λ(He+)1=R(2)2[221−421]
Given λ(H)=λ(He+)
R(1)2[n121−n221]=R(4)[221−421]
n121−n221=121−221
On comparing n1=1&n2=2