1. Formation of Ions:
* Losing Electrons: When an atom loses electrons, it becomes positively charged and forms a cation. This is because the number of protons (positive charge) now outweighs the number of electrons (negative charge).
* Gaining Electrons: When an atom gains electrons, it becomes negatively charged and forms an anion. This is because the number of electrons (negative charge) now outweighs the number of protons (positive charge).
2. Electronic Configuration:
* Loss of Electrons: The electrons lost are typically from the outermost energy level (valence shell). This results in the atom attaining a more stable electron configuration, often resembling the nearest noble gas.
* Gaining Electrons: The electrons gained are typically added to the outermost energy level, filling it up. This also leads to a more stable electron configuration, often resembling the nearest noble gas.
3. Size Change:
* Loss of Electrons: Losing electrons leads to a smaller atomic radius. This is because the positive charge in the nucleus now has a stronger pull on the remaining electrons.
* Gaining Electrons: Gaining electrons leads to a larger atomic radius. This is because the increased number of electrons creates greater electron-electron repulsion, pushing the electron cloud further from the nucleus.
4. Chemical Reactivity:
* Ions: Ions are much more chemically reactive than neutral atoms. Their charges allow them to form ionic bonds with oppositely charged ions, creating ionic compounds.
Example:
* Sodium (Na): A sodium atom has one electron in its valence shell. It readily loses this electron to become a sodium ion (Na+), achieving a stable configuration like neon (Ne). It now has a smaller atomic radius and is highly reactive, forming ionic compounds.
Conclusion:
The loss or gain of electrons fundamentally changes the structure of an atom, leading to the formation of ions, altered electronic configurations, size changes, and increased chemical reactivity. These changes allow atoms to participate in chemical bonding and form diverse molecules and compounds.
