Electrons in the outermost principal shell of an atom that are involved in chemical bonding are referred to as:
valence electrons
The electrons in the outermost principal shell of an atom that are involved in chemical bonding are referred to as valence electrons.
To determine the number of valence electrons in an atom, you need to look at the electron configuration of the element. The electron configuration tells you how the electrons are distributed in the different energy levels or shells around the nucleus of an atom.
The outermost principal shell of an atom is also known as the valence shell. It is the highest numbered shell that contains electrons. The valence electrons are those that occupy this outermost shell.
For example, let's take the element carbon (C) with an atomic number of 6. Its electron configuration is 1s2 2s2 2p2. Carbon has four valence electrons because the outermost principal shell (2s2 2p2) contains four electrons.
Knowing the number of valence electrons is important because it determines how an atom will interact with other atoms in chemical reactions. The valence electrons are the ones involved in forming chemical bonds with electrons from other atoms to create compounds.