Question

In a certain electronic transition from the quantum level 'n' to the ground state in atomic H in one or more steps, no line belonging to the Brackett series is observed. What wave numbers may be observed in the Balmer series? A) 8R/9, 5R/36 B) 3R/16, 8R/9 C) 5R/36, 3R/16 D) 3R/4, 3R/16

Answer 1

Explanation:

The n should be equal to 4; otherwise if n>4, then Bracket series will also be noticed.

Total no.of lines formed =n(n−1)/2=4∗3/2=6

No. of lines formed will be due to transition between these energy levels

n=4 to n=3

n=4 to n=2

n=4 to n=1

n=3 to n=2

n=3 to n=1

n=2 to n=1

Balmer series line obtained when any electron comes to second orbit from outer orbit so

out of these six lines, only two lines belongs to Balmer series.

i.e., from n=4 to n=2 and

n=3 to n=2

For these lines wave number is,

(i)

v

1

ˉ

=

λ

1

=R

H

[

2

2

1

−

4

2

1

]=

64

12

R

H

=

16

3

R

H

(ii)

v

2

ˉ

=

λ

1

R

H

[

2

2

1

−

3

2

1

]=

36

5

R

H

Answer 2

Answer:

not understand please explain once again