To determine the number of valence electrons for an element, you can refer to its position in the periodic table. For iodine (I) with an atomic number of 53, you can use the periodic table to find its valence electrons.
Iodine belongs to Group 17, also known as the halogens, which is located in the second-to-last column on the right side of the periodic table. The group number indicates the number of valence electrons an element has. In the case of the halogens, they have 7 valence electrons.
Since iodine is in Group 17, it has 7 valence electrons. The valence electrons are the electrons present in the outermost energy level (also called the valence shell) of an atom.
It's worth noting that the valence electrons are crucial in determining the element's chemical properties and its ability to form bonds with other elements.