Learning Objectives For Test 3

Homework. Exercises: 2-6, 9, 12, 14-18. Problems: 6, 7, 9, 11, 13, 14

Given a lattice, sketch a unit
cell.

Recognize different types of
centering.

Make a three-dimensional sketch
of the rock salt structure.

Determine the number of atoms
belonging to a given unit cell.

Given a three dimensional model of a unit cell, sketch a projection diagram, and vice versa. Exercises: 2

Describe the difference between
the two closest packed lattices, hcp and fcc. Exercises:
3

Given a model of a common
crystal structure type, describe it in terms of a lattice, and holes, and
coordination numbers. Exercises: 4, 5

Identify the locations of holes in a close-packed structure.

Know the relative number of holes.

Recognize polytypes.

Describe two non-close-packed
structures.

Recognize
polymorphism.

Describe (qualitatively) what happens to metallic (and ionic) radii when the coordination number increases (or decreases). Exercises: 6

Describe the two main types of
alloys.

Predict whether a substitutional or interstitial alloy will result when two
given elements are combined.

Given a structure, describe it
in terms of a lattice type and holes.

Given ionic radii, calculate
the radius ratio, ρ, of
a binary compound, and predict which type of structure the compound will have
by using a “radius ratio” table.
Exercises: 10, 13

Given the enthalpy changes of all but one step, determine the missing enthalpy change using a Born-Haber cycle. Exercises: 15

Given ionic radii, calculate the lattice energy of a binary ionic compound. (Madelung constants, and other constants will be given.)

Arrange simple ionic compounds in order of increasing lattice energy based on charge and size. Exercises: 19

Sketch a large cation and a
large anion.

Predict which of several compounds would be most soluble in water based on the relative sizes of the cation and anion. Exercises: 18

Account for
variation in conductivity with temperature in metals.

Explain what a
band is.

Describe how
density of states (DOS) varies through a band in three-dimensional materials.

Use the concept
of the Fermi energy distribution to explain how an intrinsic semiconductor
conducts at room temperature.

Sketch the band
structure of a p- and an n-type extrinsic semiconductor. Explain how these materials conduct as the
temperature is raised.

Recognize the five basic symmetry operations. Exercises: 1, 2, 4.

Given the point group flow chart and a molecule, determine which point group the molecule belongs to. Exercises: 3. Problems: 1

Determine the degeneracy of a representation from its symmetry label.

Determine the representation that an atomic orbital belongs to from a character table.

Use symmetry to determine if a molecule is polar, and along which axis it is polar.

Use symmetry to determine if a molecule is chiral. Problems: 2, 3

Construct simple symmetry-adapted linear combinations of atomic orbitals.

Use a character table to label symmetry-adapted linear combinations of atomic orbitals.

Use a character table to determine which orbitals can mix. Exercises: 6, 7.