Complete the sentence.
In this chemical reaction, sulfur is a ().

 - reactant
 - product
Read the underlined text carefully. Look for information about what happens to sulfur in this chemical reaction.
People have used gunpowder as an explosive for hundreds of years. Gunpowder is a mixture of three different substances: potassium nitrate, charcoal, and sulfur. When these substances are burned together, they release a large amount of heat and gas. In the past, gunpowder was used in muskets and cannons, but today, it is mainly used in fireworks.
The underlined text tells you that when potassium nitrate, charcoal, and sulfur combine, a large amount of heat and gas is released. When potassium nitrate, charcoal, and sulfur react, or go through a chemical change, their atoms are rearranged. Because sulfur reacts in this chemical reaction, sulfur is a reactant.