ATOMS AND MOLECULES

a. Atoms. Some atoms are inert or neutral atoms. They have outer shells that are completely filled with electrons. It is extremely difficult for them to combine with other atoms to form molecules. Other atoms are referred to as bonding atoms. They have less than eight electrons in their outer shell (less than two in the K shell) and combine readily with atoms of other bonding atoms. See figure 2-4.

Figure 2-4. Inert atoms and bonding atoms.