Chapter 3: Elements & Compounds

Elements

• Basic substances that cannot be broken down into simpler substances.

• Made up of atoms, which are the smallest unit of an element.

• Examples: Oxygen (O), Hydrogen (H), Carbon (C)

Compounds

• Substances formed when two or more elements combine chemically.

• Can be broken down into simpler substances.

• Examples: Water (H₂O), Carbon Dioxide (CO₂), Sodium Chloride (NaCl)

Differences between Elements and Compounds

• Elements are pure substances; compounds are combinations of elements.

• Elements consist of only one type of atom; compounds consist of different types of atoms.

• Compounds have different properties than the elements they are made from.