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Why are the atoms in ethyne arranged in a straight line?
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organic compound
The structures of organic compounds can be depicted in condensed, expanded, and three-dimensional structural formulas.
The atoms in an ethyne (also known as acetylene) molecule are arranged in a straight line because of the specific bonding environment of each carbon atom. In an ethyne molecule, each carbon atom is linked to one hydrogen atom by a single bonding pair and to the other carbon atom by a "superpair" (a triple bond consisting of three shared pairs).1
According to VSEPR theory, this arrangement results in a linear molecular geometry. From the perspective of valence bond theory, this structure is achieved through hybridization, where the carbon atoms form sp hybrid orbitals. These orbitals point in opposite directions, creating the characteristic linear shape of the molecule.12