Melting point (°C) 181
Boiling point (°C) 1347
alkali metalAny of the soft, light, reactive metals of Group 1 of the periodic table; lithium, sodium, potassium, rubidium, cesium, and francium. lyeA strong caustic alkaline solution of potassium or sodium salts, obtained by leaching wood ashes. It is much used in making soap as well as in biodiesel.