JOURNEY INSIDE THE ATOM-5

PRERNA FOR IAS

         Mehnat Aapki, Guidance Humari

         Roz ki Prelims Practice — Experts ke Saath

JOURNEY INSIDE THE ATOM-5

1. Ionic Bond

An ionic bond is a type of chemical bond formed by the transfer of electrons from one atom to another. It usually forms between a metal and a non-metal. The metal atom loses one or more electrons to become a positively charged cation, while the non-metal gains those electrons to become a negatively charged anion. The electrostatic attraction between these oppositely charged ions forms the ionic bond. Ionic compounds generally have high melting and boiling points, are hard and brittle, and conduct electricity when dissolved in water or in the molten state. Examples include sodium chloride (NaCl) and magnesium oxide (MgO).

2. Covalent Bond

A covalent bond is a chemical bond formed when two atoms share one or more pairs of electrons to achieve a stable electronic configuration. Covalent bonds usually form between non-metal atoms. Unlike ionic bonding, no electrons are transferred; instead, they are shared equally or unequally depending on the atoms involved. Covalent compounds generally have lower melting and boiling points and are poor conductors of electricity because they do not contain free ions. Common examples include water (H₂O), methane (CH₄), oxygen (O₂), and carbon dioxide (CO₂). Covalent bonding is fundamental to most biological molecules.

3. Metallic Bond

A metallic bond is the force of attraction between positively charged metal ions and a "sea" of freely moving delocalized electrons. In metals, outermost electrons are not attached to individual atoms but move freely throughout the metallic structure. This movement allows metals to conduct electricity and heat efficiently. Metallic bonding also gives metals their characteristic properties, such as high electrical conductivity, thermal conductivity, malleability, ductility, and metallic lustre. Strong metallic bonds contribute to the high melting and boiling points of many metals. Examples include iron, copper, aluminium, gold, and silver.

4. Atomic Orbit