Final answer:
The chemical bonding behavior of an atom is determined by the number and arrangement of electrons in its outermost shell. If the outermost shell is not full, the atom tends to bond with other atoms to achieve a stable configuration.
Step-by-step explanation:
The chemical bonding behavior of an atom is directly determined by the number and arrangement of electrons. The outermost shell of electrons, called the valence shell, plays a crucial role in chemical bonding. If the valence shell is full, the atom is stable and less likely to participate in chemical reactions. If the valence shell is not full, the atom is reactive and tends to bond with other atoms to achieve a full valence shell.