Environmental Chemistry

The F- ions make the enamel on teeth much harder by converting hydroxyapatite (the enamel on the surface of teeth) into much harder fluoroapatite having the formula.

1. [3 (Ca3(PO4)2) CaF2]
2. [3 (Ca3(PO4)2) Ca(OH)2]
3. [3 (Ca3(PO4)3) CaF2]
4. [3 (Ca2(PO4)2) Ca(OH)2]