Atoms "want" to be stable because nature seeks the lowest energy state for a system. This principle is known as the minimum energy principle or the principle of minimum potential energy.
In physics and chemistry, stability is associated with a lower energy state. Atoms are composed of positively charged protons in the nucleus and negatively charged electrons orbiting around the nucleus. According to the laws of electromagnetism, opposite charges attract each other, while like charges repel each other.
In an atom, electrons are attracted to the positively charged nucleus, but they also repel each other due to their negative charges. Atoms "want" to achieve a state of stability where the attractive forces between the nucleus and the electrons balance out the repulsive forces between the electrons.
By reaching a stable state, atoms minimize their total energy. Atoms can achieve stability by fulfilling certain conditions:
Filling electron shells: Atoms tend to have electron configurations that fill electron shells or orbitals. This is because filled electron shells provide a more stable arrangement. The filling of electron shells follows specific patterns based on the number of electrons each shell can hold.
Achieving a full outermost electron shell: The outermost electron shell, known as the valence shell, plays a crucial role in chemical reactions. Atoms strive to have a full valence shell by gaining, losing, or sharing electrons with other atoms. This stability arises because a full valence shell minimizes the potential for interactions and provides a more energetically favorable state.
Minimizing electrostatic repulsion: The repulsive forces between electrons within an atom can be reduced by arranging the electrons in a way that maximizes their separation. This can be achieved by distributing electrons in different orbitals or by adopting specific geometries, such as tetrahedral or octahedral arrangements in molecules.
In summary, atoms "want" to be stable because it is energetically favorable for them to achieve a state of minimum energy. Stability is associated with filling electron shells, achieving a full outermost electron shell, and minimizing electrostatic repulsion between electrons. Nature tends to favor stable configurations due to the principle of minimum energy.