Atoms Molecules and Elements

• A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number. It cannot be broken into simpler substances.
• Different elements combine to form compounds.
• Elements are classified into Metals and Nonmetals

Metals:

• Cations are positively charged species and are formed when a metal atom loses electrons.
• Cations are represented by symbol of element and positive sign as superscript (A⁺).

Sodium Cation:

Potassium Cation: