Analiza sadržaja hrvatskih kemijskih školskih knjiga u 20. stoljeću pokazuje da se elektrolitička disocijacija počela učiti 1912. godine, no kemijska veza, kao pojava koja proizlazi iz strukture atoma, pojavljuje se u sveučilišnom i srednjoškolskom udžbeniku tek 1947., 31 godinu nakon Lewisovih formula (1916.) i 21 godinu nakon Schrödingerove jednadžbe (1926.). Na uvođenje Lewisovih formula najvjerojatnije je utjecao Paulingov udžbenik “The Nature of the Chemical Bond” (1939.), a u kašnjenju našeg školskog programa za znanstvenim otkrićima ulogu su odigrale i ratne prilike (1941. – 1945.).There are two basic theories of chemical constitution; the first starts from stoichiometry (“chemical structure”), and the second from the structure of the atom (“physical structure”). In Croatian textbooks, constitution and valence of the elements were not interpreted “physically” until 1947, when the first university and the first high-school textbook with electronic Lewis formulas appeared. The late appearance of “physical structure” in Croatian textbooks – 31 years after Lewis’s first paper on the chemical bond (1916) and 14 years after the publication of his book “Valence and the Structure of Atoms and Molecules” (1923), could be explained by the hypothesis that Croatian authors were not inspired by Lewis’s work, but rather with Pauling’s textbook “The Nature of the Chemical Bond” (1939). The second factor was World War II in Croatia (1941–1945), which delayed innovations in the teaching of chemistry
