The number of spectral lines that are possible when electrons in 7th shell in different hydrogen atoms return to the 2nd shell is:

The number of spectral lines that are possible when electrons in 7^("th") shell in different hydrogen atoms return to the 2^(nd) shell is

The number of spectral lines that can be possible when electrons in 7^(th) shell in different hydrogen atoms return to the 2^(nd) shell

The number of spectral line that can be possible when electrons in 6^(th) shell in hydrogen atom return to the 2^(nd) shell :

The number of spectral lines in hydrogen atom are

Number of spectral lines in hydrogen atom is

Number of spectral lines in hydrogen atom is

Number of spectral line in hydrogen atom is .