Environment

The Most Abundant Elements In The Earth's Crust

Oxygen, silicon, and aluminium are the three most common elements in the Earth's crust.

The rigid, top layer of the Earth is called the lithosphere. It consists of the Earth’s crust and the top-most part of the mantle. Most geological activities that affect the Earth take place on the lithosphere. It is the most rigid of all of Earth’s layers. Lithosphere consists of oceanic and continental lithospheres. Oceanic lithosphere consists of Oceanic crust which forms the floors of seas and oceans while continental lithosphere consists of continental crust made of land masses. The Earth’s crust is important as it supports human and plant life and contains elements and such as aluminum which facilitate technological development. The most abundant elements in the Earth's crust are presented below:

The Most Abundant Elements In The Earth's Crust

Oxygen

Oxygen is the most abundant element in the crust at 467,100 ppm. It exists as a major compound of the silicate minerals where it combines with other elements. It also exists as a compound in carbonates and phosphates. Oxygen has industrial, medical, and commercial purposes. It is used with acetylene to cut and weld metals. It is used in hospitals to ease respiratory disease and can also be used to manufacture explosives among other numerous uses.

Silicon

Silicon is the second most common element present in the crust with an abundance of 276,900 ppm. It exists as a compound in the mantle and the crust. In the crust, it exists combined with oxygen to form silicate minerals. It is found in the sand which is an abundant and easily accessible resource on Earth. Silicon is also recovered from quartzite, mica, and talc. From silicon, we get silicones used in hydraulic fluids, electric insulators, and lubricants among others. Solid silicon is majorly used as a semiconductor especially in computer hardware. It is used to make transistors in the electronic industry. Silicon is used in the aluminum industry in the making of aluminum alloys. It is used in the production of ceramics, glass, cosmetics, insecticides, some types of steel, and pharmaceutical products.

Aluminum

At 80,700 ppm, aluminum is the third most abundant element in Earth's crust. Aluminum does not exist as a lone element, and it is found as a compound. Abundant compounds of Aluminum include aluminum oxide, aluminum hydroxide, and potassium aluminum sulfate. Aluminum is extracted from its compounds largely through the Bayer and Hall-Heroult processes. The element ideal because of its light weight and Aluminum alloys are extensively used to make utensils foils, packaging materials. It is used in the manufacture of parts of automobiles, rockets, and machinery.

Iron

Iron exists in the earth’s crust, and its composition is 50,500 ppm. Iron extracted in the form of iron ores existing in iron oxide forms such as hematite and magnetite. Blast furnaces are used to recover iron from the iron ores. Iron has many extensive applications such as the making of steel. Iron is also used to make utensils and kitchen appliances. It is also used to make cast iron and wrought iron which is extensively utilized in many industries. Iron element will always react with water and oxygen and the surface of iron is ordinarily lustrous and silvery gray, but it has a tendency of oxidizing in the open air to produce hydrated iron oxide commonly known as rust. In its purest form iron is relatively soft and is hardened and strengthened in the smelting process by adding a small percentage of carbon. The addition of carbon of between 0.002% and 2.1% will result in steel that could be 1000 times harder compared to pure iron.

Excessive Mining Leads To Environmental Degradation

Other abundant elements include: calcium (36,500 ppm), sodium (27,500 ppm), potassium (25,800 ppm), magnesium (20,800 ppm), titanium (6,200 ppm) and hydrogen (1,400 ppm). Mining involves the use of massive machinery on the earth’s surface. These types of machinery leave open pits on land and disrupt the fragile ecological system. The processes used in the mining of elements releases harmful by-products such as heavy, toxic metals to marine and land life. Excessive mining, therefore, leads to environmental degradation.

The Most Abundant Elements In The Earth's Crust

RankElementAbundance in crust (ppm)
1oxygen467,100
2silicon 276,900
3aluminium80,700
4iron50,500
5calcium36,500
6sodium27,500
7potassium25,800
8magnesium20,800
9titanium6,200
10hydrogen1,400

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