Answer: Option (b) is the correct answer.
Explanation:
Iodine is a group 7 element and its atomic number is 53. Electronic configuration of iodine is [tex][Kr]4d^{10}5s^{2}5p^{5}[/tex].
So, the outermost shell of iodine contains 7 electrons, that is, in 5s and 5p.
Whereas carbon is a group 14 element and its atomic number is 6. Electronic configuration of carbon is [tex]1s^{2}2s^{2}2p^{2}[/tex]. A carbon atom has four valence electrons.
Atomic number of hydrogen atom is 1 and there is only one valence electron.
Atomic number of helium is 2 and its electronic configuration is [tex]1s^{2}[/tex].
Thus, we can conclude that out of the given options iodine atoms contain seven valence electrons.
