Chemistry in Teaching: Arsenic and Its Compounds: Toxins, Pigments, and Medicine

Arsen je polumetal (element 15. skupine elemenata u Periodičkoj tablici elemenata), te je očekivano da će tvoriti čitav niz spojeva različitih svojstava s obzirom na vrstu kemijske veze i strukturu. U kemijskim reakcijama iskazuje metalna i nemetalna svojstva. S obzirom na Paulingov koeficijent elektronegativnosti sličan nemetalima, tvori stabilne kovalentne spojeve i s najelektronegativnijim elementima, u spojevima stvara stabilnu kovalentnu vezu As–As te tvori organoarsenove spojeve sa stabilnom vezom As–C. Primjena arsenovih spojeva bila je u prošlosti raznovrsna i višestruka. Povijesni pregled otkrivanja i uporabe arsenovih spojeva jasno poučava da se razvoj spoznaja o kemiji arsena i arsenovih spojeva temelji na znanstvenim otkrićima i napretku znanosti općenito. Organoarsenovi spojevi u prošlosti rabljeni kao lijekovi, kasnije su, razvojem znanosti, odbačeni kao otrovni i zamijenjeni naprednijim, modernijim lijekovima čija se svojstva i uporaba više ne zasnivaju na empiriji. Anorganski spojevi arsena (posebice arsenovi sulfidni minerali) primjenjivali su se kao anorganski pigmenti u slikarstvu. Takvi primjeri upotrebe spojeva kroz povijest mogu se primijeniti u srednjoškolskoj nastavi kao primjer međupredmetnih tema u kojima se povezuje kemija arsena s ekološkim i toksikološkim temama te u povijesti umjetnosti. Slično postoji i u visokoškolskom obrazovanju, posebice gdje se izučava primijenjena anorganska kemija ili u povijesti medicine i farmakologije. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna.Arsenic is metalloid (element of the 15th group of elements in the Periodic table of elements), and it is expected to form a series of compounds with different features regarding the type of chemical bond and structure. As a metalloid, it exhibits metallic and non-metallic character in chemical reactions. Arsenic is able to form covalent compounds with elements of high electronegativity considering its Pauling’s electronegativity coefficient, which is comparable to those of the non-metals, and is able to form stable As–As and As–C covalent bonds in compounds. Applications of arsenic compounds in the past have been various and multiple. The historical review of discoveries and usages of arsenic compounds clearly shows that development of arsenic chemistry is founded on scientific discoveries and improvement of science in general. The medicines in the past, and later, by scientific progress, many arsenic compounds had been rejected as toxins and replaced with more progressive, modern medicines, the features and usage of which are not based on experience of doctors and pharmacists any longer. The inorganic compounds of arsenic (especially some arsenic sulphide minerals) had been used as inorganic pigments in the art of painting. Such examples of usage of compounds through history can be used in high school education as part of intercourse themes, thus joining the chemistry of arsenic with ecological and toxicological themes, as well as the history of art. The same goes for higher education, particularly within applied chemistry courses of arsenic or within the history of medicine and pharmacology. This work is licensed under a Creative Commons Attribution 4.0 International License