CHEM 1A Lecture Notes - Lecture 5: Ionic Compound, Sphalerite, Empirical Formula

• School: UC-Irvine
• Department: Chemistry
• Course: CHEM 1A
• Professor: Ramesh D Arasasingham

Document Summary

Mini learning goal: identify the characteristics of five ionic solids by observing a model. Main learning goal: apply the characteristics of ionic solids in order to solve critical thinking questions in groups and independently. Cesium chloride: body-centered layering (not bcc unit cell, cs+ forms scc unit cell (red atoms, cl- occupies the center position (blue atom, cubic hole, atom population- Cs+: (8 corners)(1/8)= 1 cs+ atom/unit cell. Rock salt: cubic close-packed layering (fcc unit cells, cl- forms fcc unit cell (green atoms, na+ occupies all octahedral holes (blue atoms, edge positions and center position, atom population- Cl-: (8 corners)(1/8) + (6 faces)(1/2)= 4 cl-/unit cell. Na+: (12 edges)(1/4) + 1 atom in the middle= 4 na+/unit cell. Zinc blende: cubic close-packed layering (fcc unit cells, s2- forms fcc unit cell (pink atoms, zn2+ occupies half of the tetrahedral holes (purple atoms, atom population- S2-: (8 corners)(1/8) + (6 faces)(1/2)= 4 s2- atoms/unit cell.