What is a Keystone Species: Definition, Types, Characteristics, Importance, Examples, and Ecological Role

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 Introduction:      A keystone species is an organism that plays a disproportionately large role in maintaining the structure, stability, and functioning of an ecosystem. Another definition of keystone species is a species whose impact on its ecosystem is disproportionately large relative to its abundance or biomass. They are named after the keystone in a stone arch, the central wedge-shaped stone that holds the entire arch together. In 1969 zoologist Robert T. Paine used this architectural term as a metaphor to describe the critical role of these species. Although keystone species are often low in abundance, their removal can cause major changes throughout an ecosystem. Not all dominant or abundant species are keystone species. A keystone species is identified by the magnitude of its ecological impact rather than by its population size. Some keystone species are abundant, while others are relatively rare. Keystone in a stone arch History of keystone species concept...
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Introduction of Lithium: Discovery, Occurance, Properties and Applications

Introduction of Lithium:

    Lithium is an element. It is symbolize Li. In perodic table it is found in s-block, on the top of 
Group IA. It is third element in perodic table. Hence, its atomic number is 3. It is a silver-white soft alkali metal. It is also called white gold. Scientists named this mineral lithium comes from Greek word "lithios" means "stone or rock". It is named lithios because it is first alkali metal found in minerals while others like potassium and sodium was found in organic matters(in plants). 

Discovery of lithium:

    In 1790 a Brazalian scientist Joseph Boniface, on the Swedish island he discoved spodumene(LiAlSi₂O₆) and petalite(LiAlSi₄O₁₀). In 1817 a Swedish chemist John August identified lithium in petalite. In 1821 an English scientist Willian Brande isolate a trace amount of lithium through electrolysis. It wasn't isolated yet. 

Occurance of lithium:

    Lithium is an alkali metal found in rocks or minerals. It is not found in free state. Due to its high reactivity its some quantity is found in differnt minerals like spodumene and amblygonite. It is present in brines and sea water. It is 33rd most abundant elements in Earth's crust. 

Common minerals of lithium:

  • Spodumene

Physical properties:

  • Lithium is white-silvery metal.
  • It is very soft that it is easily cut by knife. It is also detransform very easily.
  • It has very low density. It can float on oil and water.
  • It is solid at room temperature.
  • Its melting point is 180.54°C, while boiling point is 1,342°C.
  • Lithium is a good electrical and heat conductor.
  • It is apear to 12-sided polyhedron cube under corrosion-free, high-current conditions.

Chemical properties:

  • Lithium is highly reactive alkali metal.
  • It has only one velence electron.
  • Lithium reacts with niterogen to form lithium nitiride.
  • It burns in flame and react with oxegen to form lithium oxide.
  • It is insoluble in some organic compound . But soluble in inorganic solvents.
  • It has very low electronegetivity of 0.98. 
  • It is rapidly tranishes in moist air and turned grey.
  • It has highest specific heat capacity(allows to absorb or transfer heat) approximately 3.58J/g.K.
  • Lithium produce crimson or carmine red colour in flame test.

Application of lithium:

    Lithium is essential for modern technology and has great importance in industries, medical and nuclear energy production.

Application in industries:

  • Due to high voltage and light weight it is used in ion battery for fast charging and long-lasting energy storage. Due to small atomic radius and high reactivity, lithium enhances efficiency of charging and discharging in batteries. Lithium ion batteries are used in grid-scale storage laptops, phones and electric vehicles. 
  • Lithium carbonate is used in making ceramics and essential for making heat-resistance glass. Lithium is used to reduce thermal expansion and increase strength.It acts as powerful flux in fibreglass. Lithium disiliate is used for high-strenght dental ceramics. Lithium reduce viscosity and improves properties of material.
  • lithium is  important component in metallergy and making alloys. It plays curcial role for remove impurities from metal. It is essential for making light-weight material for defence and aerospace. It increase strength without increasing weight.

Application in medicine:

  • Lithium carbonate is used to stabalize mood disorders because it regulate neurotransmitters. In psycosis lithium has gret importance in curing different disease. It reduce risk of sucidal behaviour. It is also used to manage mania and reduce deppresion. 
  • Lithium is also used in medical devices such as ion battery is used for powering devices,  lithium disilicate used for strengthen artificial teeth. It is also used in infusion pumps and hearing aids.
Location: Pakistan

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