Element Definition

An element is a substance made of atoms having an identical number of protons. The element cannot be decomposed by any chemical method into simpler substances. In general, the element act as a fundamental component of any entity, for example, the phloem in plants are made up of sieve element.

Etymology: The word element is derived from the Latin word “elementum” meaning “rudiment”.

Chemical Element

A pure substance that consists of only one type of atom is called an element. All the chemical elements have the fundamental building block or the smallest unit, called the “atom”.

An atom has the same number of protons in its nuclei therefore the elements made by the atoms also have a particular number of protons in their atomic nuclei. For example- An element named Carbon is made up of atoms that have the same number of protons, i.e. 6.

Examples of some common elements are iron, copper, silver, gold, copper, hydrogen, nitrogen, and oxygen. At present, there are 118 elements have been identified by scientists among which 94 are natural and 24 are synthetic elements.

The natural elements have an atomic number below or equal to 94 whereas the synthetic elements have atomic numbers beyond 94.

Element of Human Body

Living beings are mainly made up of organic molecules that include carbon, hydrogen, oxygen, and nitrogen. The human body is also made of these elements in the ratio of as follows: oxygen (65%), carbon (18.5%), hydrogen (9.5%), nitrogen (3.2%), calcium (1.5%), and phosphorus (1%).

Almost 99% of the total mass of the human body is comprised of these elements and 0.85% is comprised of other elements such as potassium (0.4%), sulfur (0.3%), sodium (0.2%), chlorine (0.2%), and magnesium (0.1%).

Substances

A substance is defined as a matter which has a definite chemical composition and distinct properties. The substance can be made of the same type of elements or maybe different types of elements in combination.

A compound is formed by elements, for example, Table salt of sodium chloride is formed by the combination of sodium and chloride atoms. These compounds include atoms that are held together by chemical bonds.

Phosphodiester Bond: Definition, Structure, and Examples

The combination of various elements results in the formation of some important compounds that are crucial to living beings such as water, salt, carbon dioxide, etc. An element can also exist in different physical forms or multiple substances can be formed by only one type of element, which is called allotropes.

Allotropes are made of similar elements however they can differ in their physical structure. For example- Carbon can form various structures such as coal, graphite, and diamond. All these compounds are made up of a similar element- carbon but they have different physical structures.

Another type of substance is alloy. A mixture of metal or non-metallic elements is called an alloy. For example- brass is the mixture of copper and zinc, similarly, bronze is also formed by mixing copper and tin.

Minerals

It is an abiogenic chemical compound that is usually found in crystalline form. A pure mineral is usually made up of an uncombined form of a mineral that has a distinct mineral structure.

For example- Gold, silver, carbon, aluminum, cobalt, copper, lead, iron, etc Minerals are also important for living organisms and act as an essential nutrient needed by our bodies.

Essential nutrients are classified into four groups: (1) vitamins (2) essential fatty acids (3) essential amino acids and (4) essential minerals. There are three types of essential elements that are macrominerals, bulk elements, and trace elements.

Bulk elements include carbon, hydrogen, oxygen, and nitrogen that have a large proportion of the human diet. As compared to bulk elements, the macrominerals are needed in lower amounts, such as calcium, phosphorous, potassium, and chlorine, etc.

The trace elements are required in a very small amount for the survival of the organism. The example of trace elements includes copper, zinc, manganese, iodine, and sulfur, etc.

Isotopes

An element can have different forms based upon the different number of neutrons within its nuclei, these forms are called isotopes. Isotopes have the same number of protons and a different number of neutrons therefore they have the same atomic number but different mass numbers.

For example, carbon can exist in three isotope forms: carbon-12, carbon-13, and carbon-14. Radioactive isotopes are known as radioisotopes. The radioisotope loses energy and emits radiation due to an unstable atomic nucleus that is called radioactive decay. The radioisotopes are used to monitor DNA replication, and also to monitor pollutants and water runoffs.

Biological Definitions

The fundamental unit or component of an entity is defined as an “element”. Sieve element in angiosperms is an example of this term. The sieve elements are the main conductive cells in the phloem.

Element Citations

• The Long-Standing Paradox of Seed Dormancy Unfolded? Trends Plant Sci . 2019 Nov;24(11):989-998.
• The role of light in regulating seed dormancy and germination. J Integr Plant Biol . 2020 Sep;62(9):1310-1326.