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Sodium facts for kids

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neonSodiummagnesium
Li

Na

K
Appearance
silvery white metallic


Spectral lines of sodium
General properties
Name, symbol, number Sodium, Na, 11
Pronunciation /ˈsdiəm/ SOH-dee-əm
Element category alkali metal
Group, period, block 1, 3, s
Standard atomic weight 22.98976928(2) g/mol
Electron configuration [Ne] 3s1
Electrons per shell 2,8,1 (Image)
Physical properties
Phase solid
Density (near r.t.) 0.968 g/cm3
Liquid density at m.p. 0.927 g/cm3
Melting point 370.87 K, 97.72 °C, 207.9 °F
Boiling point 1156 K, 883 °C, 1621 °F
Critical point (extrapolated)
2573 K, 35 MPa
Heat of fusion 2.60 kJ/mol
Heat of vaporization 97.42 kJ/mol
Specific heat capacity (25 °C) 28.230 J/(mol·K)
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 554 617 697 802 946 1153
Atomic properties
Oxidation states +1, -1
(strongly basic oxide)
Electronegativity 0.93 (Pauling scale)
Ionization energies
1st: 495.8 kJ/mol
2nd: 4562 kJ/mol
3rd: 6910.3 kJ/mol
Atomic radius 186 pm
Covalent radius 166±9 pm
Van der Waals radius 227 pm
Miscellanea
Crystal structure body-centered cubic
Magnetic ordering paramagnetic
Electrical resistivity (20 °C) 47.7 nΩ·m
Thermal conductivity (300 K) 142 W/(m·K)
Thermal expansion (25 °C) 71 µm/(m·K)
Speed of sound (thin rod) (20 °C) 3200 m/s
Young's modulus 10 GPa
Shear modulus 3.3 GPa
Bulk modulus 6.3 GPa
Mohs hardness 0.5
Brinell hardness 0.69 MPa
CAS registry number 7440-23-5
Most stable isotopes
Main article: Isotopes of Sodium
iso NA half-life DM DE (MeV) DP
22Na trace 2.602 y β+γ 0.5454 22Ne*
1.27453(2) 22Ne
ε→γ - 22Ne*
1.27453(2) 22Ne
β+ 1.8200 22Ne
23Na 100% 23Na is stable with 12 neutrons
Sodium
Sodium pellets in a container

Sodium is a chemical element with the symbol Na (from Latin natrium) and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table, because it has a single electron in its outer shell, which it readily donates, creating a positively charged ion—the Na+ cation. Its only stable isotope is Na. The free metal does not occur in nature, and must be prepared from compounds. Sodium is the sixth most abundant element in the Earth's crust and exists in numerous minerals such as feldspars, sodalite, and rock salt (NaCl). Many salts of sodium are highly water-soluble: sodium ions have been leached by the action of water from the Earth's minerals over eons, and thus sodium and chlorine are the most common dissolved elements by weight in the oceans.

Sodium was first isolated by Humphry Davy in 1807 by the electrolysis of sodium hydroxide. Among many other useful sodium compounds, sodium hydroxide (lye) is used in soap manufacture, and sodium chloride (edible salt) is a de-icing agent and a nutrient for animals including humans.

Sodium is an essential element for all animals and some plants. Sodium ions are the major cation in the extracellular fluid (ECF) and as such are the major contributor to the ECF osmotic pressure and ECF compartment volume. Loss of water from the ECF compartment increases the sodium concentration, a condition called hypernatremia. Isotonic loss of water and sodium from the ECF compartment decreases the size of that compartment in a condition called ECF hypovolemia.

Properties

Sodium is a light, silver-coloured metal. Sodium is so soft that it can be easily cut with a knife. When it is cut, the surface will become white after a bit of time. This is because it reacts with air to form sodium hydroxide and sodium carbonate. Sodium is a little lighter than water; when it reacts with water it floats. This reaction is very fast. Hydrogen and sodium hydroxide are produced. The hydrogen may ignite. Since sodium melts at a low temperature, it melts when it reacts with water. It has one valence electron which is removed easily, making it highly reactive.

Compared with other alkali metals (metals in the first column of the periodic table), sodium is usually less reactive than potassium and more reactive than lithium.

Chemical compounds

These are chemical compounds that contain sodium ions. Sodium only exists in 1 oxidation state: +1.

Discovery and name

Sodium was discovered by Sir Humphrey Davy, an English scientist, back in 1807. He made it by the electrolysis of sodium hydroxide. It is named after soda, a name for sodium hydroxide or sodium carbonate.

Use as element

It is used in the preparation of organic compounds. It is also used in the street lights that are orange, and ultra violet lights.

Use as compounds

Sodium compounds are used in soaps, toothpaste, baking and antiacids. .

Occurrence and production

Sodium does not exist as an element in nature; its easily removed valence electron is too reactive. It exists as an ion in chemical compounds. Sodium ions are found in the ocean. It is also found as sodium chloride in the earth's crust, where it is mined.

Sodium is normally made by electrolysis of very hot sodium chloride that was melted.

Use in organisms

Sodium ion in the form of sodium chloride is needed in the human body, but large amounts of it cause problems, which is why one should not eat too much salt. Many organisms in the ocean depend on the proper concentration of ions in sea water to live.

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