What Is a Chemical Reaction and Why Does It Matter?

A chemical reaction is when substances transform into new substances with different properties.
Atoms rearrange during reactions, breaking old bonds and forming new ones.
Everyday examples include rusting iron, baking bread, and digesting food.
Chemical reactions power life itself—respiration in cells is a constant reaction.
Energy changes are central: some reactions release heat, others absorb it.
Photosynthesis is a vital reaction, turning sunlight, water, and CO₂ into food.
Industrial reactions create fuels, plastics, medicines, and countless daily products.
Even our emotions rely on chemical reactions in the brain involving neurotransmitters.
Balancing chemical equations ensures conservation of mass—atoms aren’t lost.
Understanding reactions helps solve global challenges like clean energy and medicine.