Manganese is essential to iron and steel production by virtue of its
sulfur-fixing, deoxidizing, and alloying properties. Steelmaking, including
its ironmaking component, has accounted for most manganese demand, presently
in the range of 85% to 90% of the total demand. Among a variety of other
uses, manganese is a key component of low-cost stainless steel formulations
and certain widely used aluminium alloys.
Like the other alkali metals, potassium reacts violently with water
producing hydrogen. The reaction is notably more violent than that of
lithium or sodium with water, and is sufficiently exothermic that the
evolved hydrogen gas ignites.
2K(s) + 2H2O(l)
H2(g) + 2KOH(aq)
Because potassium reacts quickly with even traces of water, and its
reaction products are nonvolatile, it is sometimes used alone, or as NaK (an
alloy with sodium which is liquid at room temperature) to dry solvents prior
to distillation. In this role, it serves as a potent desiccant.
Sodium is relatively abundant in stars and the D spectral lines of this
element are among the most prominent in star light. Sodium makes up about
2.6% by weight of the Earth's crust making it the fourth most abundant
element overall and the most abundant alkali metal.
At the end of the 19th century, sodium was chemically prepared by heating
sodium carbonate with carbon to 1100 °C.
Na2CO3 (liquid) + 2 C (solid, coke)
2 Na (vapor) + 3 CO (gas).