Sodium (Na)
Sodium is soft enough to cut with a butter knife and is stored under oil because it reacts with water.
Sodium properties
- Atomic mass
- 22.99 u
- Category
- Alkali metal
- Group
- 1
- Period
- 3
- Block
- s-block
- State at room temp.
- Solid
- Electronegativity
- 0.93
- Melting point
- 370.94 K (97.8 °C)
- Boiling point
- 1,156.09 K (882.9 °C)
- Density
- 0.968 g/cm³
- Atomic radius
- 227 pm
- Ionization energy
- 5.139 eV
- Electron affinity
- 0.548 eV
- Radioactive
- No, has stable isotopes
- Discovered
- 1807
Sodium electron configuration
- Electron configuration
- [Ne] 3s1
- Full electron configuration
- 1s2 2s2 2p6 3s1
- Electron shells
- 2 · 8 · 1
The electron configuration of Sodium (Na) is [Ne] 3s1. Its 11 electrons are arranged in shells as 2, 8, 1.
Protons, neutrons and electrons in Sodium
A neutral Sodium atom has 11 protons and 11 electrons. Most Sodium atoms have about 12 neutrons: the atomic mass rounded to 23, minus the atomic number 11.
Neutrons are approximate: atoms of the same element can have different numbers of neutrons (isotopes). Atomic number and mass
How many valence electrons does Sodium have?
1
Sodium has 1 valence electron in its outermost shell, shell 3. These are the electrons involved in chemical bonding.
Sodium orbital diagram
Each box is an orbital that holds up to two electrons with opposite spins (↑↓). The inner shells are the same as the noble gas in brackets. How to write electron configurations
Molar mass of Sodium
22.99 g/mol
One mole of Sodium atoms (6.022 × 10²³ atoms) has a mass of 22.99 grams. Use this value to convert between grams and moles.
Compounds containing Sodium
Sodium facts
- Sodium is soft enough to cut with a butter knife and is stored under oil because it reacts with water.
- Sodium (Na) has atomic number 11 and is a solid at room temperature. It was discovered in 1807.
Position in the periodic table
Sodium is element 11, in period 3 and group 1 of the periodic table, in the s-block.
Uses of Sodium
Sodium is used mostly through its compounds: sodium chloride (table salt) seasons and preserves food and de-ices roads, and sodium hydroxide is used to make soap, paper and aluminum. Baking soda is sodium bicarbonate, and soda ash (sodium carbonate) is a main ingredient of ordinary glass. Sodium vapor lamps give older streetlights their orange-yellow glow, and liquid sodium metal cools some nuclear reactors.
Who discovered Sodium?
Humphry Davy first isolated sodium in 1807 at the Royal Institution in London, by passing an electric current through molten sodium hydroxide (caustic soda). He had isolated potassium the same way just days earlier.
Where does the name come from?
Humphry Davy named sodium in 1807 after soda (caustic soda), the compound he isolated it from. Its symbol, Na, comes from the New Latin natrium, based on natron, a natural soda mineral known since ancient times.
Same group
Compare Sodium
FAQ
What is the electron configuration of Sodium?
The electron configuration of Sodium (Na) is [Ne] 3s1. Its 11 electrons are arranged in shells as 2, 8, 1.
How many protons, neutrons and electrons does Sodium have?
A neutral Sodium atom has 11 protons and 11 electrons. Most Sodium atoms have about 12 neutrons: the atomic mass rounded to 23, minus the atomic number 11.
How many valence electrons does Sodium have?
Sodium has 1 valence electron in its outermost shell, shell 3. These are the electrons involved in chemical bonding.
What is the molar mass of Sodium?
The molar mass of Sodium is 22.99 g/mol. This is the same number as its atomic mass, 22.99 u.
Is Sodium a metal?
Yes. Sodium is an alkali metal, so it is a metal.
Is Sodium radioactive?
Ordinary Sodium is not radioactive: it has at least one stable isotope. Like every element, it also has radioactive isotopes, most of them made in laboratories.
Where is Sodium on the periodic table?
Sodium is element 11, in period 3 and group 1 of the periodic table, in the s-block.