Question

Which of the following atoms contains seven valence electrons?

carbon
iodine
hydrogen
helium

Answer 1

Answer: Option (b) is the correct answer.

Step-by-step explanation:

Iodine is a group 7 element and its atomic number is 53. Electronic configuration of iodine is
`[Kr]4d^(10)5s^(2)5p^(5)`.

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
`1s^(2)2s^(2)2p^(2)`. 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
`1s^(2)`.

Thus, we can conclude that out of the given options iodine atoms contain seven valence electrons.

Answer 2

I believe the correct answer from the choices listed above is the second option. Iodine atoms contains seven valence electrons. Iodine is one of the members of Group 17,which are usually called as Halogens. All but seven are in the inner shells of the iodine atom.