Tag: nak

NaK, or sodium-potassium alloy, an alloy of potassium (K) and sodium (Na), is usually liquid at room temperature. Various commercial grades are available. NaK is highly reactive with water and may catch fire when exposed to air, so must be handled with special precautions, but is not really explosive and not spreading radioactivity like water in reactors at accident cases.
NaK containing 40% to 90% potassium by weight is liquid at room temperature. The eutectic mixture consists of 77% potassium and 23% sodium, is liquid from −12.6 to 785°C, and has a density of 866 kg/m³ at 21°C and 855 kg/m³ at 100°C, making it less dense than water. It is highly reactive with water and is stored under dry nitrogen (or, even better, dry argon) for safety reasons.
When stored in air, it forms a yellow potassium superoxide coating and may ignite. This superoxide reacts explosively with organics. NaK is not dense enough to sink in most hydrocarbons, but will sink in lighter mineral oil. It is unsafe to…