Kaksiksidemeid

Kaksiksidemeid, meaning "double bonds" in Estonian, refers to a covalent chemical bond between two atoms involving four shared electrons. This is in contrast to a single bond, which involves two shared electrons. Double bonds are typically stronger and shorter than single bonds between the same two atoms. For example, the carbon-carbon double bond in ethene (C2H4) is stronger and shorter than the carbon-carbon single bond in ethane (C2H6).

The presence of double bonds significantly influences the chemical and physical properties of molecules. They are often found in unsaturated organic compounds, such as alkenes and alkynes. In alkenes, a double bond consists of one sigma (σ) bond and one pi (π) bond. The pi bond is formed by the sideways overlap of p-orbitals and is weaker than the sigma bond, which is formed by the direct overlap of atomic orbitals. This pi bond is more reactive and is the site where many addition reactions occur, such as hydrogenation or halogenation.

In contrast, alkynes contain a triple bond, which consists of one sigma bond and two pi bonds. The concept of double bonds is fundamental to understanding organic chemistry, molecular geometry, and reaction mechanisms. They are crucial for the diversity of organic compounds and their roles in biological systems and industrial processes. The electronic configuration and spatial arrangement dictated by double bonds are key to predicting a molecule's behavior.