molekulid

Molekulid, or molecular compounds, are substances composed of two or more atoms held together by chemical bonds. These compounds can be formed from elements of the same kind (such as diatomic oxygen, O₂) or different elements (such as water, H₂O). Unlike ionic compounds, which involve the transfer of electrons, molecular compounds arise primarily from the sharing of electrons between atoms, known as covalent bonding.

The properties of molecular compounds vary widely depending on their structure and composition. Many are found in everyday life, including gases like nitrogen (N₂), liquids like ethanol (C₂H₅OH), and solids like sugar (C₁₂H₂₂O₁₁). These compounds often exhibit lower melting and boiling points compared to ionic compounds due to weaker intermolecular forces, such as dipole-dipole interactions or London dispersion forces.

Molecular geometry, determined by theories like VSEPR (Valence Shell Electron Pair Repulsion), influences the shape and reactivity of these compounds. For example, the bent shape of water (H₂O) results from lone pair repulsion, affecting its polarity and solubility in water.

Molecular compounds play a crucial role in biology, chemistry, and industry. Organic chemistry, a branch of chemistry focused on carbon-containing compounds, primarily deals with molecular substances. They are essential in pharmaceuticals, plastics, and fuels, driving advancements in materials science and medicine. Understanding their structure and bonding is fundamental to fields like biochemistry, where complex molecules like DNA and proteins regulate biological processes.