Sodium (Na) is one of the most important and reactive metals on Earth. It is essential for human life and forms the base of countless chemical compounds.
The atomic number of Sodium is 11, meaning its nucleus contains exactly 11 protons.
Atomic Number: 11.
Symbol: Na.
Atomic Mass: 23 u.
Electronic Configuration: 2, 8, 1.
Valency: 1 (loses 1 electron to form Na⁺ ion).
| Property | Value |
|---|---|
| Symbol | Na (from Latin 'Natrium') |
| Atomic Number | 11 |
| Atomic Mass | 23 u |
| Electronic Configuration | 2, 8, 1 |
| Valency | 1 |
| Group | Group 1 (Alkali Metals) |
| Period | Period 3 |
Sodium has only 1 electron in its outermost shell (configuration: 2, 8, 1). It desperately wants to lose this single electron to achieve a stable configuration of 8 electrons (like Neon). This makes it extremely reactive — it reacts violently with water: 2Na + 2H₂O → 2NaOH + H₂↑
The atomic number of sodium (Na) is 11.
Because sodium has 1 electron in its outermost shell, which it readily loses to form a stable Na⁺ ion.
The electronic configuration of sodium is 2, 8, 1 (2 electrons in the first shell, 8 in the second, and 1 in the third).
What is Chain Isomerism? Organic Chemistry Explained
Learn what chain isomerism is in organic chemistry. Understand structural isomers with clear examples like Pentane, Isopentane, and Neopentane.
What is a Double Displacement Reaction? (Class 10)
Learn what a Double Displacement reaction is in Chemistry. Understand the mutual exchange of ions, precipitation reactions, and examples for Class 10 Science.
What is Eau de Cologne? (Chemistry and Uses)
Learn what Eau de Cologne is. Understand the chemical composition of perfumes, the concentration of essential oils in alcohol, and why it fades quickly.
What is Hydrogenation? (Addition Reaction)
Learn what Hydrogenation is in Carbon and its Compounds. Understand the industrial addition reaction of adding hydrogen to vegetable oil to make Vanaspati Ghee.
What is Ionization Enthalpy? Definition and Trends
Understand the definition of Ionization Enthalpy (Ionization Energy) in chemistry. Learn how it changes across periods and groups in the periodic table.
Turn this guide into revision flashcards, a practice exam, or an AI-generated podcast — free, no signup required.