The wavelength of the first spectral line in the Balmer series of hydrogen atom is 6561 Å. The wavelength of the second spectral line in the Balmer series of singly- ionized helium atom is :

The wavelength of the first spectral line in the Balmer series of hydr

1.	The wavelength of the first spectral line in the Balmer series of hydrogen atom is 6561 Å. The wavelength of the second spectral line in the Balmer series of singly- ionized helium atom is :
Answer» 1215 Å 1640 Å 2430 Å 4687 Å Solution :`1/(6561)=R (1/4-1/9)=(5R)/(36)` `1/lambda=4R (1/4-1/(16))=(3R XX 4)/(16)` `lambda=1215Å`

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The wavelength of the first spectral line in the Balmer series of hydrogen atom is 6561 Å. The wavelength of the second spectral line in the Balmer series of singly- ionized helium atom is :

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