A sodium cation is formed when a sodium atom loses an electron.
Understanding how a sodium cation comes into being involves looking at the behavior of a sodium atom at the atomic level. According to the reference provided, a sodium atom loses one electron from the outermost shell and forms a sodium ion. This resulting ion is positively charged and is known as a cation.
The Process of Sodium Cation Formation
Sodium (Na) is an alkali metal with an atomic number of 11. This means a neutral sodium atom has 11 protons (positive charge) and 11 electrons (negative charge). These electrons are arranged in specific energy shells around the nucleus.
Here's a breakdown of the process:
- Starting Point: A neutral sodium atom (Na). It has a balanced charge because the number of protons equals the number of electrons.
- Electron Loss: The outermost electron in a sodium atom is relatively far from the nucleus and is not held very tightly. The atom can easily lose this one electron.
- Formation of Ion: When the sodium atom loses one electron from its outermost shell, it no longer has an equal number of protons and electrons. It still has 11 protons, but now it only has 10 electrons (11 - 1 = 10).
- Resulting Charge: With 11 positive charges (protons) and 10 negative charges (electrons), the overall charge of the particle becomes +1 (11 - 10 = +1).
- Identifying the Ion: A positively charged ion is called a cation. Therefore, the particle formed is a sodium cation, represented as Na⁺.
Key Transformation:
| Property | Sodium Atom (Na) | Sodium Cation (Na⁺) |
|---|---|---|
| Protons | 11 | 11 |
| Electrons | 11 | 10 |
| Net Charge | 0 (Neutral) | +1 (Positive) |
| Type of Particle | Atom | Cation (Ion) |
Why Does Sodium Lose an Electron?
Atoms tend to achieve a stable electron configuration, often resembling that of noble gases. Sodium is in Group 1 of the periodic table, meaning it has one electron in its outermost shell. By losing this single electron, the sodium atom achieves a full outer shell, similar to the electron configuration of the noble gas Neon (Ne). This loss makes the ion more stable.
This process is fundamental in the formation of ionic compounds like table salt, sodium chloride (NaCl), where a sodium atom transfers its outermost electron to a chlorine atom.
