What happens:
* Rearrangement of atoms: The atoms within the original substance break apart and rearrange to form new molecules.
* Formation of new bonds: New chemical bonds form between the rearranged atoms, resulting in a new compound.
* Energy change: Chemical changes typically involve either the release (exothermic) or absorption (endothermic) of energy.
* Irreversibility: While some chemical changes can be reversed, many are irreversible.
Examples:
* Burning wood: Wood (cellulose) reacts with oxygen to produce carbon dioxide, water, and ash. The wood has transformed into different substances with different properties.
* Baking a cake: Flour, sugar, eggs, and other ingredients combine and undergo chemical reactions, creating a new substance with a different texture, flavor, and appearance.
* Rusting of iron: Iron reacts with oxygen and water to form iron oxide (rust), a substance with different properties than iron.
Key points to remember:
* A chemical change results in a new substance with different properties.
* The original substance is no longer present.
* Chemical changes often involve the release or absorption of energy.
* Chemical changes can be difficult or impossible to reverse.
Let me know if you have any other questions about chemical changes!
