User:Chloe Crusit

= Combination reaction or synthesis =

Combination reaction or synthesis
is a chemical change two or more elements combine to form a new substance. Combustion, an example of combination, happens when elements or compounds burn, and then combine with oxygen to form a new compound. For example, when you burn charcoal, the carbon in the charcoal combines with oxygen in the air. The newly formed compound is now carbon dioxide.

Another example of combination is when certain elements or compounds are in contact with one another. For instance, when sodium is in contact with water, hydrogen gas is released and the compound sodium hydroxide is formed.