Question

The frequency of first line of Balmer series in hydrogen atom is V° .The frequency of corresponding let be emitted by singly ionised helium atom is ​

Answer 1

Answer:

4v°

Explanation:

We know v=c/lambda

And by the formula ,

1/lambda=R(Z^2) (1/n1^2- 1/n2^2)

=> V°=Rc(Z^2) (1/n1^2- 1/n2^2)

Here Z= atomic number.

For helium aromic number = 2

Therefore,

In case 1: v=v°, Z=1

So, v°= Rc(1^2) (1/2^2- 1/3^2). [ As it is in the Balmer series, where n1= 2 and n2=3]

Case 2:

v=x , Z =2 ( for helium)

So, x= Rc(2^2)(1/2^2- 1/3^2)

Now, from case 1 and 2 we have,

V°/x= 1/2^2

=> x=4v°