No, a chlorine atom in its elemental form is not stable.
Understanding Atomic Stability
Atoms strive to achieve a stable electron configuration, which typically means having a full outer electron shell. This state is often referred to as having an octet of electrons (eight electrons) in the outermost shell, though there are exceptions for very small atoms.
Why Chlorine is Unstable
Based on the provided reference, the reason a chlorine atom is not stable is due to its electron arrangement:
- A chlorine atom has 7 electrons in its outermost electron shell (also known as the valence shell).
- To reach a stable state, it needs a full outer shell, which requires 8 electrons for chlorine.
- Since it is missing one electron to complete its octet, the chlorine atom is highly reactive and actively seeks to gain or share an electron.
This drive to achieve stability explains why chlorine is usually found in nature not as single atoms, but bonded with other atoms in molecules or ionic compounds, such as in table salt (sodium chloride, NaCl) or chlorine gas (Cl₂).
Achieving Stability
Chlorine atoms typically achieve stability through chemical bonding:
- Gaining an electron: A chlorine atom can gain an electron from another atom (like sodium), forming a negatively charged chloride ion (Cl⁻). This ion now has a full outer shell (8 electrons) and is stable.
- Sharing electrons: Two chlorine atoms can share one pair of electrons to form a diatomic molecule (Cl₂). Each atom effectively "sees" 8 electrons in its outer shell through this covalent bond, making the molecule stable.
In summary: While chlorine atoms are not stable individually due to having an incomplete outer electron shell, they readily form bonds to achieve stability as ions or molecules.
