Here's why:
* Iron sulfide (FeS) is formed. This is a chemical reaction, not just a physical mixture. The iron and sulfur atoms combine to create a new compound with different properties than either element alone.
The reaction is as follows:
Fe (iron) + S (sulfur) → FeS (iron sulfide)
Important Note: The reaction requires the right conditions:
* Heat: The reaction needs enough heat to provide the energy needed to break the bonds in the iron and sulfur atoms and allow them to form new bonds.
* Powdered form: The reaction occurs more readily if the iron and sulfur are in a powdered form, providing more surface area for the reaction to take place.
The result:
* The resulting iron sulfide is a solid substance with a distinct black color, different from the original grey iron and yellow sulfur.
So, it's not that no substance is formed, but rather that a new substance, iron sulfide, is formed when iron and sulfur are heated together.
