The main-group elements include the elements in the p-block and s-block of the periodic table, as shown in the image below. These are the elements whose lightest members are represented by helium, lithium, beryllium, boron, carbon, nitrogen, oxygen, and fluorine. They are sometimes called the representative elements because they display a wide range of physical and chemical properties. They are also the most abundant elements in the universe, solar system, and on Earth.
!Periodic table with main group elements highlighted)
The f-block and d-block elements are not part of the main group. They are called the inner transition metals and the transition metals, respectively. They have different electronic configurations and chemical behaviors than the main group elements.