Chemistry: The Periodic Table and Elements

Periodic Table

• The periodic table is a chart that organizes elements by their atomic number and properties.
• The vertical columns of the periodic table are called Groups and are numbered 1 to 8.
• "A series" elements are representative or main group elements.
• "B series" elements are transition or subgroup elements.
• Group 1A metals are called the alkali metals.
• Group 2A metals are called the alkaline earth metals.
• Group 7A elements are called the halogens.
• Group 8A elements are called the rare gases or noble gases.

Elements

• Each horizontal row of the periodic table is called a period.
• The Lanthanide series consists of elements cerium (Z = 58) to lutetium (Z = 71).
  • The lanthanide series is also sometimes called the rare earth series.
• The Actinide series consists of elements thorium (Z = 90) to lawrencium (Z = 103).

Electron Configuration

• 1s is the first energy level in the electron shell.