Chemical Reactions and Physical Changes

Substances change when they are heated. Sometimes they react with other substances (like the iron and sulfur). This is a chemical reaction. Sometimes, though, the heat just causes the substance to melt, evaporate or sublime. This is called a physical change.

Today, we heated sugar to see if we could melt it. We heated some more sugar to see if we could caramelise it.

Melted Sugar (left)
Caramelised Sugar (right)
Solid Sugar (middle)

SOURCE: George, Alex, Jack G and Thomas B