The name Barium originates from Greek word barys which means “heavy”. It was identified as a new element in 1774, but not reduced to a metal until 1808 with the advent of electrolysis. It is a chemical element with symbol Ba and atomic number 56. It is the fifth element in group 2 and is a soft, silvery alkaline earth metal. Because of its high chemical reactivity, It is never found in nature as a free element. Its hydroxide, known in pre-modern times as baryta, does not occur as a mineral, but can be prepared by heating barium carbonate.
- It is a soft, silvery-white metal, with a slight golden shade when ultrapure. The silvery-white color of barium metal rapidly vanishes upon oxidation in air yielding a dark gray oxide layer.
- Ba has a medium specific weight and good electrical conductivity. Ultrapure barium is very difficult to prepare, and therefore many properties of barium have not been accurately measured yet.
- At room temperature and pressure, Ba has a body-centered cubic structure, with a barium–barium distance of 503 picometers, expanding with heating at a rate of approximately 1.8×10−5/°C.
- Its melting temperature of 1,000 K (730 °C; 1,340 °F) is intermediate between those of the lighter strontium (1,050 K or 780 °C or 1,430 °F) and heavier radium (973 K or 700 °C or 1,292 °F); however, its boiling point of 2,170 K (1,900 °C; 3,450 °F) exceeds that of strontium (1,655 K or 1,382 °C or 2,519 °F).
Barium Chemical Characteristics
- Ba is chemically similar to magnesium, calcium, and strontium, but even more reactive. It always exhibits the oxidation state of +2.
- Reactions with chalcogens are highly exothermic (release energy); the reaction with oxygen or air occurs at room temperature, and therefore barium is stored under oil or in an inert atmosphere.
- Reactions with other nonmetals, such as carbon, nitrogen, phosphorus, silicon, and hydrogen, are generally exothermic and proceed upon heating.
- Reactions with water and alcohols are very exothermic and release hydrogen gas.