Abstract: The invention concerns a valence-electron-model in shape of a molecular-building-set and its use for early learning and teaching purposes at schools and universities. In the molecular-building-set each electron is preferentially enabled to form a chemical bond and is represented by a radical-neutral-connecting-element, each plus-charge is represented by plus-charge-connecting-elements and each minus-charge is represented by a minus-charge-connecting-element. Free electron-pairs are represented by two electron-representations in shape of an electron-pair-representation. Binding-forces between electron-pairs and basic-atomic-body-representations are represented by electron-pair-connecting-elements and basic-atomic-body-connecting-elements. Radical-neutral-connecting-elements are in a preferred embodiment shaped as radical-neutral-plugs with C3n-rotational-symmetry.