The green glow is emitted by phosphorus, atomic number 15, in the presence of oxygen, atomic number 8. Luc Viatour, Creative Commons License
Phosphorus is the element that is atomic number 15 on the periodic table. Phosphorus is an element that is essential for human life and found in many everyday products.
Atomic Number 15 Element Facts
The symbol for element 15 is P.
The element was discovered by alchemist Hennig Brand who was seeking another element, gold. Phosphorus originally was purified from human urine. The method involves collecting a large volume of urine, evaporating off the water, heating the residue, and collecting and condensing the phosphorus-rich vapor.
Phosphorus is a reactive element that is found in chemical compounds. It does not occur naturally in pure form.
The name “phosphorus” comes from the Greek word ‘phosphoros,’ which means bringer of light. The name refers to the way white phosphorus glows green in air. The word phosphorescence comes from the element name, although phosphorus emits lights from chemiluminescence and not phosphorescence!
Phosphorus is a solid at room temperature and pressure. However, it can take one of four forms or allotropes: red, white, yellow, and black/violet. These forms exhibit different characteristics. Black phosphorus is the least reactive allotrope. This form of element 15 resembles the graphite used in pencils. White phosphorus spontaneously oxidizes in air, causing it to glow green. White phosphorus is also extremely toxic. Red phosphorus is used in the strikers of modern safety matches. The “safety” part is that these matches do not spontaneously combust, plus they are considerably less poisonous than the old type of matches that used white phosphorus. However, red phosphorus spontaneously changes into white phosphorus when heated, so match strikers are not categorically safe. One interesting project you can do (preferably wearing gloves) is to purify phosphorus from match strikers to make glowing smoke appear to come from your fingers.
Element 15 is a nonmetal. Phosphorus often appears waxy or crumbly. It is a poor conductor of electricity and is not ductile or malleable.
Natural phosphorus consists entirely of one stable isotope — phosphorus-31. 18 isotopes are known, with atomic masses ranging from 26 to 43.
Commercial uses of phosphorus include fertilizer, phosphor bronze, fireworks, light-emitting diodes, tracer bullets, incendiary devices, detergents, and baking powder. It’s also an ingredient in methamphetamine. The element is essential for human, animal, and plant nutrition. It is the 6th most abundant element in living organisms. In humans, it is necessary for bones, teeth, the backbone of DNA, in cell membranes, and in the energy molecule, ATP. However, people get phosphorus by ingesting the element in compounds — skin contact with pure phosphorus causes chemical burns.
The average adult human body contains about 26.5 ounces (750 grams) of phosphate, mostly stored in the bones of the skeletal system.
Scientists believe much of the phosphorus found in the Earth’s crust came from meteorites that contained phosphorus compounds.