Final answer:
Chemical bonds are broken and formed during chemical reactions. When a chemical bond is broken, it requires energy, and when a chemical bond is formed, energy is released.
Step-by-step explanation:
A chemical bond is the physical process that causes atoms and molecules to be attracted to each other and held together in more stable chemical compounds. During a chemical reaction, bonds are broken and formed. When a chemical bond is broken, energy is required, and when a chemical bond is formed, energy is released.