How many valence electrons does an iodine atom have

Explanation:

Iodine is a halogen so it is the group (column number) 17 of the periodic table. It is a representative element.

The number of valence electrons for the representative elements is equal to the second digit of the group number. So, group 17 means that iodince has 7 valence electrons.

Now, more formally, the valence electrons are the electrons in the outermost shell of the atom and you can determine how many of them an atom has by doing the electron configuration.

These are the steps:

the answer is c. nacl