Molecular Orbital Organic Structures Set. Molyorbital™ model collection set containing Benzene, Ethane, Ethene and Ethyne. This set contains sufficient parts to make the organic molecular orbital models, as shown in the picture. The models show: sigma bonding orbitals, pi bonding orbitals, concept of hybridisation and delocalisation. Contents: 12 carbon and 18 hydrogen atoms, carbon-carbon (oval shaped) sigma bonds, 18 carbon-hydrogen (pear shaped) sigma bonds, pi-bonds (21 pink and 21 purple pieces). Dimensions: Benzene diameter 20cm, height 10cm.