Question 252: Atoms & Nuclei

Question

If $$\lambda$$1 and $$\lambda$$2 are the wavelengths of the third member of Lyman and first member of the Paschen series respectively, then the value of $$\lambda$$1 : $$\lambda$$2 is :

Accepted Answer

For Lyman series
n
1
= 1, n
2
= 4
$${1 \over {{\lambda _1}}} = R\left[ {{1 \over {{1^2}}} - {1 \over {{4^2}}}} ight]$$
For paschen series
n
1
= 3, n
2
= 4
$${1 \over {{\lambda _2}}} = R\left[ {{1 \over {{3^2}}} - {1 \over {{4^2}}}} ight]$$
$$ 	herefore $$ $${{{\lambda _1}} \over {{\lambda _2}}} = {{\left[ {{1 \over 9} - {1 \over {16}}} ight]} \over {\left[ {1 - {1 \over {16}}} ight]}} = {7 \over {9 	imes 15}}$$
$$ \Rightarrow $$ $${{{\lambda _1}} \over {{\lambda _2}}} = {7 \over {135}}$$

Answer

7 : 135

Answer

7 : 108

Answer

1 : 9

Answer

1 : 3

Atoms & Nuclei

If $\lambda1 and \lambda2 are the wavelengths of the third member of Lyman and first member of the Paschen series respectively, then the value of \lambda1 : \lambda$2 is :

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