EOSC 114 Lecture Notes - Lecture 26: Ionic Radius, Corundum, Substitution Reaction
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Appreciate the three common ways of reporting a mineral"s composition (e. g. atom basis, atomic weight basis, and oxide weight basis) Report amount of cation in weight percent (wt %) of its oxide form: can report composition by, atom basis, atomic weight basis, oxide basis. Report the same information, but in different formats. Appreciate that element substitutions occur in minerals and describe the difference between simple and coupled substitution. The goldilocks principle not too big, not too small, but just right! Simple substitution: when one element substitutes for just one other. Coupled substitution: more than two elements are involved. : fe and ti (net charge +3) replacing al (+3) in corundum (al2o3) Occur because chemical compounds must remain charge neutral. State the two main properties that must be similar between elements in order for substitution to occur in a mineral: charge (+/-, ionic radius ( )