Barium facts for kids

Quick facts for kids
Barium, ₅₆Ba

Barium
Pronunciation	/ˈbɛəriəm/ ​(BAIR-ee-əm)
Appearance	silvery gray; with a pale yellow tint
Standard atomic weight Ar, std(Ba)	137.327(7)
Barium in the periodic table
Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson Sr ↑ Ba ↓ Ra caesium ← barium → lanthanum
Atomic number (Z)	56
Group	group 2 (alkaline earth metals)
Period	period 6
Block	s
Electron configuration	[Xe] 6s2
Electrons per shell	2, 8, 18, 18, 8, 2
Physical properties
Phase at STP	solid
Melting point	1000 K ​(727 °C, ​1341 °F)
Boiling point	2118 K ​(1845 °C, ​3353 °F)
Density (near r.t.)	3.51 g/cm3
when liquid (at m.p.)	3.338 g/cm3
Heat of fusion	7.12 kJ/mol
Heat of vaporization	142 kJ/mol
Molar heat capacity	28.07 J/(mol·K)
Vapor pressure P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 911 1038 1185 1388 1686 2170
Atomic properties
Oxidation states	+1, +2 (a strongly basic oxide)
Electronegativity	Pauling scale: 0.89
Ionization energies	1st: 502.9 kJ/mol 2nd: 965.2 kJ/mol 3rd: 3600 kJ/mol
Atomic radius	empirical: 222 pm
Covalent radius	215±11 pm
Van der Waals radius	268 pm
Spectral lines of barium
Other properties
Natural occurrence	primordial
Crystal structure	​body-centered cubic (bcc)
Speed of sound thin rod	1620 m/s (at 20 °C)
Thermal expansion	20.6 µm/(m⋅K) (at 25 °C)
Thermal conductivity	18.4 W/(m⋅K)
Electrical resistivity	332 nΩ⋅m (at 20 °C)
Magnetic ordering	paramagnetic
Molar magnetic susceptibility	+20.6·10−6 cm3/mol
Young's modulus	13 GPa
Shear modulus	4.9 GPa
Bulk modulus	9.6 GPa
Mohs hardness	1.25
CAS Number	7440-39-3
History
Discovery	Carl Wilhelm Scheele (1772)
First isolation	Humphry Davy (1808)
Main isotopes of barium
Iso­tope Abun­dance Half-life (t1/2) Decay mode Pro­duct 130Ba 0.11% (0.5–2.7)×1021 y εε 130Xe 132Ba 0.10% stable 133Ba syn 10.51 y ε 133Cs 134Ba 2.42% stable 135Ba 6.59% stable 136Ba 7.85% stable 137Ba 11.23% stable 138Ba 71.70% stable

Corroded barium metal

Barium is a chemical element with the number 56 on the periodic table. Its special symbol is Ba. It has 56 protons and 56 electrons. Its weight is about 137.3. Barium is a type of metal.

What is Barium?

Physical Features

Barium belongs to a group of elements called alkaline earth metals. It is a shiny, silver-colored metal. However, it quickly turns black when exposed to air. Barium is soft and can be easily shaped, which means it is ductile. It can mix with other metals to form special mixtures called alloys.

How Barium Reacts

Barium is a very reactive metal. If you leave pure barium metal in the air, it will react with oxygen. First, it turns black, then it becomes white as a new substance called barium oxide forms. Barium also reacts with water, creating barium hydroxide and hydrogen gas. It reacts very quickly with acids, making a barium salt and hydrogen. If you burn barium in air, it can form barium peroxide.

Barium can also react with many other metal oxides and sulfides. This creates barium oxide or sulfide and the original metal. At high temperatures, it even reacts with carbon and nitrogen to form barium cyanide.

Barium Compounds

Because barium metal is so reactive, you won't find it as a pure metal in the Earth. Instead, it is always found as part of chemical compounds. Barium always has a charge of +2 when it forms compounds. Most barium compounds are clear or colorless.

Be careful! Many barium compounds that dissolve in water or stomach acid are very poisonous. However, Barium sulfate is different. It does not dissolve in water or acids, which makes it special. Barium compounds are quite heavy. When heated until they are red-hot, barium compounds produce a bright greenish flame.

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  Barium chloride

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  Barium sulfate

Where is Barium Found?

Barium sulfate as barite

Barium is found in the ground as two main minerals: barium sulfate (also known as barite) and barium carbonate (called witherite). Both of these minerals do not dissolve in water. Barium sulfate is especially hard to dissolve in anything. You can find a lot of barium in countries like China, Germany, India, Morocco, and the US.

How is Barium Made?

It is quite difficult to get pure barium metal from barium sulfate. So, barium sulfate is first changed using carbon to create barium sulfide and carbon dioxide. This barium sulfide is then dissolved in hydrochloric acid. This process makes hydrogen sulfide and barium chloride.

Next, the barium chloride is melted. Then, a process called electrolysis is used. This means electricity is passed through the melted barium chloride to separate it, giving us liquid barium metal. The liquid barium metal then cools down and becomes solid. It is stored in oil to keep it from reacting with air.

Barium carbonate, the other mineral, is easier to work with. It is dissolved in hydrochloric acid to make barium chloride and carbon dioxide. Then, just like before, the barium chloride is melted and electrolyzed to get pure barium metal.

What is Barium Used For?

As a Metal

Barium metal is used to remove oxygen from things like old cathode ray tubes (found in older TVs) and vacuum tubes. It is placed inside these tubes and reacts with any oxygen, using it all up. Barium is also used in spark plug wires in cars.

As Chemical Compounds

Some compounds of barium, like barium sulfate, are not poisonous. This means they can be safely put into the human body. Doctors use barium sulfate to help them see inside the body using X-rays. When someone swallows a special liquid containing barium sulfate, it shows up clearly on X-rays. This helps doctors find problems like blockages in the stomach or intestines. Barium sulfate absorbs the X-rays, creating a clear image of the inside of the body. This method gives a good picture with less radiation than some other scans. Barium sulfate can also be used as a pigment to add color to things.

Other barium compounds have many different uses in various industries.

Is Barium Safe?

Barium is a very toxic element, meaning it can be dangerous. There is a tiny amount of barium in our food, but this small amount does not cause problems. However, if we get barium from other places, it can cause serious health issues. Even a small amount, like 1 gram of barium, can be deadly.

Barium is dangerous because it acts like other very important elements in our body, such as calcium and magnesium. If barium replaces these important elements, it can mess up how our body works.

Images for kids

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  Sir Humphry Davy, who first isolated barium metal

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  Benitoite crystals on natrolite. The mineral is named for the San Benito River in San Benito County where it was first found.

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  Amoebiasis as seen in a radiograph of a barium-filled colon

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  Green barium fireworks

See also

In Spanish: Bario para niños