Barium, like all the other alkaline earth metals, is soft and silvery (however forms a very dark grey colour upon oxidation unlike most other alkaline metals), reacts with water violently and is not found in its elemental form in nature due to its high reactivity. However, it exhibits interesting properties, such as YBCO, a high-temperature superconductor which was one of
the first alloys to exhibit these properties.
In photometry, the flame colour of Barium is green and does not have many spectral overlaps
with other ions that a flame photometer analyses routinely making its analysis simple and
easy.
Electronically Barium is found in the 2+ state in pretty much every case that you can think of
apart from rare and unstable cases it is found in the +1 state such as Barium Fluoride gas,
which is very unstable.
Barium discovery is interesting due to it being commonplace to use it during alchemy. Rocks
that washed up on the beaches of southern Italy due to a large amount of volcanic rock found
there. It had been used for around 170 years before in 1774 it was thought to contain new
element humanity had never isolated before. Multiple attempts were made to isolate barium,
however, due to it being strongly bound to oxygen, the closest that they got to isolating it was
Barium Oxide. It was Humphry Davey who initially isolated the element via molten
electrolysis of barium salts.
Other claims to fame that barium has is that Barium Sulphate was the very first thing to be
used to develop x-rays the digestive tract in 1908.
Barium production is usually done from Baryte rocks, which are commonly found in
England, China, Romania and also most of the former USSR. However, only 8% of all baryte
mined in modern times is used to make Barium and it is found in low concentrations in both
seawater as well as the outer crust of the earth.
Barium in commercial use, however, is limited. It was used as a way to ensure that residual
gasses from vacuum tubes are removed, as barium sulphate is highly reactive to most gasses
found in the earth atmosphere, Oxygen, CO2, Water and Nitrogen. It also exhibits properties
that can trap noble gasses. However, as the commercial use of vacuum tubes has died with
the rise in LCD screen displays, barium is not commonly found in day to day commercial
locations.