Sulfur is classified as a nonmetal due to a combination of its physical and chemical properties:

Physical Properties:

* Brittle: Sulfur is solid at room temperature and breaks easily into small pieces.

* Poor conductor of heat and electricity: This is a characteristic of nonmetals.

* Dull appearance: Sulfur has a yellow color and a powdery texture, unlike the shiny appearance of most metals.

Chemical Properties:

* Low electronegativity: Sulfur has a relatively low electronegativity compared to metals. This means it has a weaker attraction for electrons.

* Forms anions (negatively charged ions): Sulfur readily gains electrons to form negatively charged ions, like sulfide (S^2-). This is a typical characteristic of nonmetals.

* Forms covalent bonds: Sulfur forms covalent bonds with other nonmetals, sharing electrons to form molecules like sulfur dioxide (SO₂).

* Reacts with metals to form sulfides: Sulfur reacts with metals to form ionic compounds called sulfides. This is a characteristic of nonmetals interacting with metals.

Overall, sulfur exhibits more characteristics of nonmetals than metals, leading to its classification as a nonmetal.