Based on its position in the periodic table, the element sulfur would be expected to have how many valence electrons?

Sulfur has six valence electrons.

When determining the number of valence electrons based on the element's position on the periodic table, you have to look at it's group. Starting on the left with group one and two, they have (you guessed) one and two valence electrons based on their group. Skipping the D-block elements, the next group (group 13) has three valence electrons, fourteen has four, and so on until the noble gasses, group sixteen, have a full valence shell, or eight valence electrons.