Answer:
A compound
Example:
Sugar contains carbon, hydrogen and oxygen. Water (H2O) has two hydrogen atoms (H2) and one oxygen atom (O). So both sugar and water are chemical compounds. Together they are a mix of chemical compounds.
chemical change occur when a substance combines with another to form a new substance.
Explanation:
hope this helps ;)
b.plasma
they jump in a exited energy level and by doing that they give off light