What is the atomic number of Sodium?

Sodium has atomic number 11, which means a neutral atom has 11 protons and 11 electrons.

What is the chemical symbol for Sodium?

The chemical symbol for Sodium is Na.

What category is Sodium in?

Sodium is classified as a alkali metal and sits in period 3 of the periodic table.

Element 11

Sodium (Na)

Sodium is a chemical element with symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal.

Atomic Number

Atomic Mass

22.99 u

Period

Group

Group 1: alkali metals and hydrogen

Phase

solid

Density

0.968 g/cm3

Electron Shells

2, 8, 1

Atomic Structure

Protons: 11. Electrons: 11. Neutrons: Varies by isotope.

Electron configuration: 1s² 2s² 2p⁶ 3s¹

Why Sodium Matters

Sodium helps connect atomic number 11, alkali metal behavior, period 3 trends, and electron shell structure. Its solid phase, atomic mass of 22.99 u, and electron configuration 1s² 2s² 2p⁶ 3s¹ make it useful for comparing bonding patterns across the periodic table.

Discovery and Occurrence

Sodium was discovered 1807 by Humphry Davy. Sodium is a chemical element with symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal.

Safety and Handling Context

Sodium is in a highly reactive family. Pure alkali metals can react strongly with water, so demonstrations belong in controlled lab settings.

Related Elements

Frequently Asked Questions

What is the atomic number of Sodium?: Sodium has atomic number 11, which means a neutral atom has 11 protons and 11 electrons.
What is the chemical symbol for Sodium?: The chemical symbol for Sodium is Na.
What category is Sodium in?: Sodium is classified as a alkali metal and sits in period 3 of the periodic table.

Explore Sodium in 3D

Use the interactive table above to rotate atomic models, compare periodic trends, and move from Sodium to neighboring elements without losing your place.