Question

Whay is the longest wavelength of lyman series of hydrogen spectrum

Answer 1

Answer:

5/27.

Transition to n=1 and n=2 are refered to as Lyman and Balmer series.

For Lyman Series wavelength will be longest when energy the electron has transition from n=2 to n=1 level.

For Balmer Series wavelength will be longest when energy the electron has transition from n=3 to n=2 level.

E

2

−E

1

∝(−

1

2

1

+

2

2

1

)=

4

3

E

3

−E

2

∝(−

3

2

1

+

2

2

1

)=

36

5

E

3

−E

2

E

2

−E

1

=

36

5

4

3

=

5

27

Hence,

λ

B

λ

L

=

27

5

as E∝

λ

1