One-valent

In chemistry, 'one-valent' (also known as 'monovalent') describes an atom or radical that can form one covalent bond. This means it can share one electron with another atom, resulting in a chemical bond. The term is typically used to characterize the bonding capacity or valence of an atom, reflecting its ability to combine with other atoms. The concept helps to predict the stoichiometry of molecules and understand their chemical properties. It's a fundamental concept in understanding molecular structure and chemical reactions.

One-valent meaning with examples

• Hydrogen (H) is a classic example of a one-valent element. Each hydrogen atom has one valence electron, allowing it to form a single bond, as seen in the H₂ molecule. This single bonding capacity makes hydrogen fundamental in numerous chemical compounds.
• The chloride ion (Cl⁻), a halide, is one-valent. It can form one covalent bond due to its single negative charge and the presence of an unpaired electron, seen when binding with sodium to produce the compound Sodium Chloride, or table salt.
• In the formation of hydrochloric acid (HCl), the hydrogen atom, as one-valent, combines with the one-valent chlorine atom to form a single covalent bond, illustrating the concept of combining valence.
• The hydroxyl radical (OH) acts as one-valent. It contains a single unpaired electron, which can bind to other molecules. This allows it to form a single bond, which helps when forming compounds like methanol (CH₃OH).
• In methane (CH₄), each hydrogen atom is one-valent, forming one bond with the carbon atom. This bonding configuration makes methane a simple hydrocarbon with a tetrahedral geometry.