Elements for Kids
Phosphorus is the second element in the fifteenth column of the period table. It is classified as a nonmetal. Phosphorus atoms have 15 electrons and 15 protons with 5 valence electrons in the outer shell.
- Symbol: P
- Atomic Number: 15
- Atomic Weight: 30.97376
- Classification: Nonmetal
- Phase at Room Temperature: Solid
- Density: white: 1.823 grams per cm cubed
- Melting Point: white: 44.1°C, 111°F
- Boiling Point: white: 280°C, 536°F
- Discovered by: Hennig Brandt in 1669
Characteristics and Properties
Phosphorus is a highly reactive element and, as a result, is never found on Earth as a free element. Elemental phosphorus comes in various allotropes (different crystal structures) including white, red, violet, and black phosphorus. The two major forms of phosphorus are white and red.
White phosphorus is very reactive and unstable. White phosphorus is yellowish in color and is highly flammable. It will spontaneously ignite when it comes into contact with air. White phosphorus glows in the dark and is also very toxic.
Red phosphorus is generally more stable than white. It is also less toxic and doesn't spontaneously ignite when coming into contact with air. Red phosphorus is made by heating white phosphorus.
Where is phosphorus found on Earth?
Phosphorus is not found in its pure elemental form on Earth, but it is found in many minerals called phosphates. Most commercial phosphorus is produced by mining and heating calcium phosphate. Phosphorus is the eleventh most abundant element in the Earth's crust.
Phosphorus is also found in the human body. It is the sixth most abundant element in the human body.
How is phosphorus used today?
The primary use of phosphorus in industry is in the manufacture of fertilizers. This is because phosphorus is a key element in the growth of plants.
Red phosphorus is used in making pesticides and safety matches.
Other applications for phosphorus include baking powder, the alloy phosphor bronze, flame retardants, incendiary bombs, and LEDs (light emitting diodes).
Phosphorus is an important element in the functioning of the human body and is essential for life. It is used in the DNA molecule and is a main ingredient in our bones and teeth. We get phosphorus from foods such as beans, nuts, eggs, fish, milk, and chicken.
How was it discovered?
Phosphorus was discovered by German alchemist Hennig Brandt in 1669. He was hoping to create a legendary substance called the philosopher's stone. He stumbled across phosphorus while conducting experiments with urine.
Where did phosphorus get its name?
Phosphorus gets its name from the Greek word "phosphoros" meaning "bringer of light." Henning Brandt picked this name because the element glowed in the dark.
The only stable phosphorus isotope is phosphorus-31. It has twenty-three known isotopes.
Interesting Facts about Phosphorus
- It used to be a major ingredient in detergents, but the phosphates caused algae to grow in rivers and lakes, killing many fish. Few detergents still use phosphates today.
- Touching white phosphorus can cause severe burns.
- Similar to the cycles of oxygen, carbon, and nitrogen, there is also a phosphorus cycle that is important to plant and animal life.
- Hennig Brandt was the first person to be given credit for discovering an element.
- Black phosphorus looks like graphite powder and conducts electricity even though it is not a metal.
- The majority of phosphate rock mined in the United States comes from Florida and North Carolina.
More on the Elements and the Periodic Table
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