- Elements List
- Aluminium, Al
- Antimony, Sb
- Arsenic, As
- Barium, Ba
- Beryllium, Be
- Bismuth, Bi
- Boron, B
- Cadmium, Cd
- Calcium, Ca
- Carbon, C (Graphite)
- Cerium, Ce
- Cesium, Cs
- Chromium, Cr
- Cobalt, Co
- Copper, Cu
- Dysprosium, Dy
- Erbium, Er
- Europium, Eu
- Gadolinium, Gd
- Gallium, Ga
- Germanium, Ge
- Gold, Au
- Hafnium, Hf
- Holmium, Ho
- Indium, In
- Iridium, Ir
- Iron, Fe
- Lanthanum, La
- Lead, Pb
- Lithium, Li
- Lutetium, Lu
- Magnesium, Mg
- Manganese, Mn
- Mercury, Hg
- Molybdenum, Mo
- Neodymium, Nd
- Nickel, Ni
- Niobium, Nb
- Osmium, Os
- Palladium, Pd
- Phosphorus, P
- Platinum, Pt
- Potassium, K
- Praseodymium, Pr
- Rhenium, Re
- Rhodium, Rh
- Rubidium, Rb
- Ruthenium, Ru
- Samarium, Sm
- Scandium, Sc
- Selenium, Se
- Silicon, Si
- Silver, Ag
- Sodium, Na
- Strontium, Sr
- Sulphur, S
- Tantalum, Ta
- Tellurium, Te
- Terbium, Tb
- Thallium, Tl
- Thorium, Th
- Thulium, Tm
- Tin, Sn
- Titanium, Ti
- Tungsten, W
- Vanadium, V
- Ytterbium, Yb
- Yttrium, Y
- Zinc, Zn
- Zirconium, Zr
Barium, Ba
Description
Barium is a chemical element. It has the symbol Ba, and atomic number 56. Barium is a soft silvery metallic alkaline earth metal. It is never found in nature in its pure form due to its reactivity with air. Its oxide is historically known as baryta but it reacts with water and carbon dioxide and is not found as a mineral. The most common naturally occurring minerals are the very insoluble barium sulfate, BaSO4 (barite), and barium carbonate, BaCO3 (witherite). Benitoite is a rare gem containing barium.
Barium is a metallic element that is chemically similar to calcium but more reactive. This metal oxidizes very easily when exposed to air and is highly reactive with water or alcohol, producing hydrogen gas. Burning in air or oxygen produces not just barium oxide (BaO) but also the peroxide. Simple compounds of this heavy element are notable for their high specific gravity. This is true of the most common barium-bearing mineral, its sulfate barite BaSO4, also called 'heavy spar' due to the high density (4.5 g/cm³).
Available Forms:
| Technical Data | ||||||||
| Symbol | Be | Density (20°C)/gcm-3 | 1.848 | |||||
| Atomic number | 4 | Melting point / °C | 1287 | |||||
| No. of naturally occurring isotopes | 1 | Boiling point / °C | ~2500 | |||||
| Atomic weight | 9.01218 | ΔHfus/kJmol-1 | 15 | |||||
| Electronic configuration | [He] 2s2 | ΔHvap/kJmol-1 | 309 | |||||
| Ionization energy/kJmol-1 | 899.2 | Eo(M2-(aq)2e- →M(S))/V | -1.85 | |||||
| II | 1757 | Electrical resistivity | ||||||
| Metal radius/pm | 112 | (20°C)/μohm cm | 4.46 | |||||
| Ionic radius (4-coord)/pm | 27 | |||||||
| Evaporation Techniques | ||||||||
| Temperature (oC) @Vap. Pressure | Techniques | Remarks | ||||||
| 10-8 Torr | 10-6 Torr | 10-4 Torr | Electron Beam | Crucible | Coil | Boat | ||
| 545 | 627 | 735 | Fair | Metals | Tungsten | Molybdenum, Tantalum & Tungsten | Wets w/o alloying – reacts with ceramics. Go to Evaporation Sources Page | |
Unit 12, Hassocks Wood, Basingstoke, Hampshire, RG24 8UQ, UK. High Purity Materials For Research, Development and Industry
© 2008 Testbourne Limited
