Covalensi

Covalensi is a term used in chemistry to describe the sharing of electrons between atoms. This sharing creates a chemical bond, known as a covalent bond, which holds the atoms together to form molecules. Covalent bonds are typically formed between nonmetal atoms, as they have similar electronegativities, meaning they have a comparable pull on electrons.

The number of covalent bonds an atom can form is determined by its valence electrons, which are the electrons in the outermost shell of an atom. Atoms tend to form covalent bonds to achieve a stable electron configuration, often resembling that of the noble gases, which have a full outermost electron shell. For example, carbon, with four valence electrons, commonly forms four covalent bonds to achieve a stable octet.

Covalent bonds can be single, double, or triple, depending on the number of electron pairs shared between two atoms. A single covalent bond involves the sharing of one pair of electrons, a double bond involves the sharing of two pairs, and a triple bond involves the sharing of three pairs. The strength of a covalent bond increases with the number of shared electron pairs.

Molecules formed by covalent bonds exhibit a wide range of properties. For instance, water (H2O) is a polar molecule due to unequal sharing of electrons between oxygen and hydrogen atoms, leading to its unique properties as a solvent. In contrast, methane (CH4) is a nonpolar molecule because the electrons are shared equally between carbon and hydrogen atoms. The study of covalent bonding is fundamental to understanding the structure, properties, and reactions of a vast array of chemical substances.