Reported by:

JOY FULGAR

Phosphorus Cycle

Phosphorus was discovered by Hennig Brand at 1669 in Germany. Origin of name: from the Greek word "phosphoros" meaning "bringer of light" 

Brand kept his process a secret, phosphorus was discovered independently in 1680 by an English chemist, Robert Boyle.

•Atomic Number: 15

•Atomic Weight: 30.973762

•Melting Point: 317.30 K (44.15°C or 111.47°F)

•Boiling Point: 553.65 K (280.5°C or 536.9°F)

•Density: 1.82 grams per cubic centimeter

•Phase at Room Temperature: Solid

•Element Classification: Non-metal

•Period Number: 3    

•Group Number: 15    

•Group Name: Pnictogen

A multivalent pnictogen, phosphorus as a mineral is almost always present in its maximally oxidized state, as inorganic phosphate rocks. Elemental phosphorus exists in two major forms—white phosphorus and red phosphorus—but due to its high reactivity, phosphorus is never found as a free element on Earth.

In nature, Phosphorus exists in form of phosphate.

White Phosphorus is used in some explosives, including rockets. This caused an uproar because of safety concerns.

Red Phosphorus is used in match heads. You can see the texture of a match head next to the matches.

Fertilizer; Phosphorus is known for being essential to DNA and to a lesser extent fertilizer

It is an essential nutrient for plants and animals.

It is a part of DNA-molecules and RNA-molecules, molecules that store energy (ATP and ADP)

It is also a building block of certain parts of the human and animal body, such as the bones and teeth.

• Ecological Function Phosphorus is an essential nutrient for plants and animals. Limiting nutrient for aquatic organisms.

Forms parts of important life-sustaining molecules that are very common in the biosphere.

• Biological Function The primary biological importance of phosphates is as a component of nucleotides, which serve as energy storage within cells (ATP) or when linked together, form the nucleic acids DNA and RNA..

The biogeochemical cycle that describes the movement of phosphorus through

the lithosphere, hydrosphere, and biosphere. Unlike many other biogeochemical cycles,

the atmosphere does not play a significant role in the movement of phosphorus, because

phosphorus and phosphorus-based compounds are usually solids at the typical ranges of

temperature and pressure found on Earth.

Visualization of the Cycle

PHOSPHORUS CYCLE

1. Reservoir – erosion transfers phosphorus to water and soil; sediments and rocks that accumulate on ocean floors return to the surface as a result of uplifting by geological processes

2. Assimilation – plants absorb inorganic PO43-

(phosphate) from soils; animals obtain organic phosphorus.

3. Release – plants and animals release phosphorus when they decompose; animals excrete phosphorus in their waste products

Effects of Human Activities on the Phosphorous Cycle

We remove large amounts of phosphate from the earth to make fertilizer.

We reduce phosphorous in tropical soils by clearing forests.

We add excess phosphates to aquatic systems from runoff of animal wastes and fertilizers. (causes eutrophication)

EUTROPHICATION

REVIEW

1. When rocks high in phosphorus are exposed to water, the rock weathers out and goes into solution

2. Autotrophs absorb this phosphorus and use it in many different ways,

3. Then the plant is eaten by a heterotroph and obtains phosphorus from the plant

4. Then the phosphate leaves the body, and decomposers move the phosphorus into the soil or water then another plant will absorb this phosphorus.