Here's why:

* Lewis Dot Structures: These diagrams represent the valence electrons (electrons in the outermost shell) of an atom. They are shown as dots surrounding the element's symbol.

* Sulfur (S): Sulfur has 6 valence electrons. Its Lewis dot structure would have 6 dots around the "S" symbol.

* Selenium (Se): Selenium is in the same group (Group 16) as sulfur on the periodic table. This means they have the same number of valence electrons. Selenium also has 6 valence electrons, making its Lewis dot structure identical to sulfur's.

Other elements in Group 16 (oxygen, tellurium, polonium) would also have similar Lewis dot structures, although their reactivity and properties differ from sulfur and selenium.