- An element cannot be decomposed into two or more different substances by simple chemical methods
- Sulfur cannot be decomposed into different substances by simple chemical methods
- Therefore, sulfur is a kind of element

Hence, sulfur is a kind of element
Q: Because sulfur cannot be decomposed by simple chemical methods into two or more different substances, it is classified as
Context:
- An element cannot be decomposed into two or more different substances by simple chemical methods 
- Sulfur cannot be decomposed into different substances by simple chemical methods