Question

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Answer 1

The frequency of sodium is given :-

• $\sf\green{{\nu=2.09\times10^{-14}\ s^{-1}}}$

Here,we know the speed of light is:-

• $\sf\green{{v=3\times10^8\ m\,s^{-1}}}$

The wavelength of the light is given by :-

• $\sf\red{\lambda=\dfrac{v}{\nu}}$

Now,we need to put the given value of frequency.

$:\implies\sf{\lambda=\dfrac{3\times10^8}{2.09\times10^{-14}}}$

$:\implies\sf{\lambda=14.35\times10^{21}\ m}$

$:\implies\sf{\lambda=14. 35\times10^{21+9-9}\ m}$

$:\implies\sf{\lambda=14.35\times10^{30-9}\ m}$

$:\implies\sf{\lambda=14.35\times10^{30}\times10^{-9}\ m}$

$:\implies\underline{\sf\red{{\lambda=14. 35\times10^{30}\ nm}}}$

Answer 2

1+5/9 { LCM of 9 }

1 + 5

9

==. 6/9

==. 2/3