Metals
- 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
+44 (0)1256 467055
+44 (0)1256 842929
info@testbourne.com
Potassium, K
Description
Potassium is a chemical element. It has the symbol K (Arabic: al qalja → Latin: kalium) and atomic number 19. The name "potassium" comes from the word "potash", as potassium was first isolated from potash. Potassium is a soft silvery-white metallic alkali metal that occurs naturally bound to other elements in seawater and many minerals. It oxidizes rapidly in air and is very reactive, especially towards water. In many respects, potassium and sodium are chemically similar, although organisms in general, and animal cells in particular, treat them very differently.
Available Forms:
| Technical Data | ||||||||
| Symbol | K | Melting point /°C | 63.2 | |||||
| Atomic number | 19 | Boiling point /°C | 765.5 | |||||
| No. of naturally occurring isotopes | 2+1* | ΔHfus/kJmol-1 | 2.39 | |||||
| Atomic weight | 39.0983 | ΔHvap/kJmol-1 | 79 | |||||
| Electronic configuration | [Ar]4s1 | ΔHf(monoatomic gas)/kJmol-1 | 90 | |||||
| Metal radius/pm | 227 | ΔH(dissoc)/kJmol-1 | 49.9 | |||||
| Ionic radius(6-coordinate)/pm | 138 | Ionization energy/kJmol-1 | 418.6 | |||||
| Eo(M+(aq)+e- →M(S))/V | -2.925 | *(radioactive 4°K t1/2 1.27 x 109 y) | ||||||
| Density (20°C)/gcm3 | 0.856 | |||||||
| Evaporation Techniques | ||||||||
| Temperature (oC) @Vap. Pressure | Techniques | Remarks | ||||||
| 10-8 Torr | 10-6 Torr | 10-4 Torr | Electron Beam | Crucible | Coil | Boat | ||
| 842 | 992 | 1192 | Excellent | Al2O3 | Tungsten | Tungsten | Alloys with refractory metals; rapid Evaporation suggested. Spits in EB. 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
