## Chemistry and Chemical Reactivity (9th Edition)

a) It's a cubic shape with atoms in every face: face-centered cubic. b) Each anion is surrounded by 4 cations, so they are in tetrahedral holes c) Calcium: $8\times 1/8=1$ ions in the vertexes, $6\times 1/2=3$ in the faces, 4 in total Fluorine: 8 inside the cell Formula: $CaF_2$