Chemical Properties of Elements

An element can be distinguished by its chemical properties like the atomic number, atomic mass, boiling point, etc, which depend on the number of protons (positively charged ions) present in its nucleus. The term element is generally referred to a pure chemical substance comprised of atoms, with an equal number of protons and electrons. Till now, 117 elements have been discovered, out of which 94 occur naturally on the Earth. Some common examples of elements are carbon, copper, iron, hydrogen, nitrogen, silver, oxygen, etc.

Chemical Properties of Elements
The chemical properties of an element are as follows:

Atomic Number
The atomic number of an element shows the number of protons present in the core of an atom. It is an important concept of chemistry and quantum mechanics. An element and its position in the periodic table depends on its atomic number. When an atom is electrically neutral, the atomic number equalizes the number of electrons (negatively charged ions) present around the core of the atom.

Atomic Mass
The atomic mass represents the mass of an atom which is measured in atomic mass units (amu). The mass of an element depends on the protons and the neutrons present in the nucleus of an element. The weight of a proton or neutron is about 1 amu, hence the atomic mass is nearly equal to the mass or nucleon number. The atomic mass of an isotope represents the number of neutrons present in the nucleus.

Electronegativity
During a chemical bonding between two atoms, the tendency of an atom to force the electronic cloud in its direction is called as electronegativity. According to the Pauling's scale, the element fluorine has the highest electronegativity of value 4.0 and francium has the lowest electronegativity of value 0.7.

Density
The density of an element is defined as the number of units of mass, of the element present in a certain volume of a medium. The density of an element depends on temperature and pressure, hence it is generally expressed graphically with these two properties. Density is measured in kilograms per cubic meter (kg/m3).

Melting Point
The melting point is defined as the temperature at which an element changes its state from solid to liquid. At this point, the solid and the liquid state of an element exist in equilibrium.

Boiling Point
The boiling point is defined as the temperature at which the liquid form of an element equalizes with the gaseous form. At this temperature, the liquid and the gaseous state exist in equilibrium.

Electronic Configuration
The electronic configuration of an element indicates the arrangement of the electrons in circles around the core. Each circle has a fixed energy level, electrons away from the core have high energy levels whereas electrons closer to the core, have low energy levels. These circles are not perfectly round and are divided into shells and sub-shells.

Standard Potential
The standard potential of an element is defined as the potential of a redox reaction, when the element is at equilibrium. If the potential exceeds zero, it is an oxidation reaction, else a reduction reaction. The standard potential is measured in volt (V) and expressed by the symbol V⁰.

The chemical property of an element, reflect the substance's quality, that becomes evident during a chemical reaction. These properties help us understand the nature and behavior of an element under different conditions.