A tetrahedron in my bag!

Abstract

The construction of a physical model of a tetrahedron starting from a plastic bag is presented. The model can be applied in the learning teaching of symmetry and stereochemistry of simple molecules possessing atoms with a tetrahedral arrangement of their valence shell’s electron pairs, such as oxygen in water, nitrogen in ammonia and carbon in methane. Enclosing balls, a tetrahedral skeletal model or simple air in the tetrahedral bag is possible to achieve different applications of the model, including the funny and harmless explosion of the bag.