Chemical reactions involve breaking and forming bonds between atoms.

Reactants change into products during a chemical reaction.

Energy is either absorbed or released in chemical reactions.

Some reactions happen quickly, others take a long time.

Catalysts speed up chemical reactions without being used up.

Exothermic reactions release heat; endothermic reactions absorb heat.

Chemical reactions can change color, produce gas, or form a precipitate.

Balancing chemical equations shows the conservation of atoms.

Photosynthesis is a chemical reaction where plants make food.

Rusting of iron is a chemical reaction with oxygen and water.