Final answer:
Oxygen and sulfur, both in group 16 of the periodic table, have 6 valence electrons each. They follow the octet rule to achieve a full valence shell, often by gaining or sharing electrons in chemical bonds.
Step-by-step explanation:
To determine the number of valence electrons in neutral atoms such as oxygen and sulfur, we use the periodic table. The oxygen atom, which is in group 16 (also known as group 6A), has 6 valence electrons. Similarly, the sulfur atom, which is also in group 16, has the same number of valence electrons as oxygen, which is 6 valence electrons. These valence electrons are important for bonding as they participate in forming chemical bonds with other atoms.
To predict how these atoms will combine with other elements, we can look at the octet rule. This rule states that atoms tend to combine in such a way that each atom has 8 electrons in its valence shell. In the case of oxygen and sulfur, they will try to gain or share 2 more electrons to achieve a full valence shell.
For polyatomic ions or molecules with charges, you would add or subtract electrons from the total valence count accordingly. In more complex molecules or ions, drawing a Lewis structure will help to visualize the distribution of electrons and predict the molecular arrangement.