This handout set of atom models with connecting rods is used in chemistry lessons in middle and senior classes to reproduce the spatial structure of molecules of organic and inorganic substances. It helps students picture how a molecule is built, understand the valency of atoms, the multiplicity of chemical bonds and the phenomenon of isomerism. The set is sized for one student at a workstation and suits individual as well as group work, which students carry out under the supervision of the chemistry teacher.
The set has 92 parts in total: 52 atom spheres and 37 connecting rods, covering 6 kinds of elements. Large spheres are 23 mm in diameter and small spheres 17 mm. Short rigid rods for single bonds are 27 mm long, and long flexible rods for double and triple bonds are 43 mm long. Spheres are made of impact-resistant plastic and rods of polymer. Every sphere is drilled with holes set at defined angles, so a model reproduces real molecular geometry and keeps the correct valence angles, bond directions, shape and structure: linear 180°, angular 105°, trigonal 120°, trigonal pyramidal 107°, tetrahedral 109°28′, trigonal bipyramidal 120°/90° and octahedral 90°. The colouring of the spheres follows the international colour code for chemical elements, so an element is easy to recognise in an assembled model.
The set includes 52 atom spheres, 37 connecting rods, 3 petal-shaped p-orbital parts, a passport with a warranty card, and individual transport packaging. Beige universal spheres with sp², sp³, dsp³ and d²sp³ hybridisation serve as substitutes for elements supplied in smaller numbers. The set is ready for use and needs no assembly.
For a single bond a rigid 27 mm rod is pushed into the hole of one sphere as far as it goes and the second sphere is fitted onto the free end. For a double bond two flexible 43 mm rods join the same pair of atoms, and for a triple bond three of them; flexible rods form an arc when inserted, which matches the real geometry of the molecule. The petal-shaped p-orbital parts are fitted into the sphere holes to show the shape and spatial orientation of p-orbitals in bond formation. Models are taken apart by pulling the rods along the axis of the hole rather than sideways.
The set needs no power supply and works indoors in an educational institution at an air temperature of +5 to +40 °C and relative humidity of 40 to 60 % without condensation. It is not intended for children under 36 months, as it contains small parts that can be swallowed, and the ends of the rods can be sharp. Parts are wiped with a dry or slightly damp soft cloth; abrasives and organic solvents such as acetone, alcohol and toluene damage the plastic and the colour coating. Parts are not heated, as the material degrades above +50 °C. Marking and operating documentation are in Ukrainian, the packaging is an individual corrugated cardboard box with content fixing, the service life is 5 years and the warranty period is 12 months.
