Why were Avogadro’s ideas not widely accepted at first?

Amedeo Avogadro’s hypotheses, first proposed in 1811, were not immediately accepted by the scientific community for several key reasons:

• Abstract Nature and Anomalies: His ideas were considered distressingly abstract and were burdened by certain anomalies that hindered their adoption.1
• Resistance to Physical Methods: Many chemists were reluctant to utilize physical methods, such as vapor-density determinations, to resolve chemical problems.1
• Influence of Jöns Jacob Berzelius: The authority of the eminent Swedish chemist Jöns Jacob Berzelius posed a significant barrier. Berzelius incorrectly contended that atoms of similar elements repelled each other due to identical electric charges, leading him to believe that only atoms with opposite charges could combine to form molecules.2
• Lack of Consensus: Because chemists lacked a reliable way to determine the number of atoms in a molecule, the field was characterized by a chaotic multiplicity of competing, incompatible systems for atomic weights and chemical formulas.21

It was not until 1858 that Stanislao Cannizzaro demonstrated how Avogadro’s theory could construct a consistent theoretical structure, eventually leading to widespread acceptance following the 1860 Karlsruhe Congress.21