Exam 18: The Solid State a Particulate View

In a two-component alloy the more abundant metal can be thought of as the solvent while the less abundant metal can be thought of as the solute.Which of the following would NOT change the orientation of atoms in the solvent's unit cell? I.a solute with the same atomic radius as the solvent II.a solute that was sufficiently small to fit into holes in the solvent's unit cell III.a solvent that was sufficiently small to fit into holes in the solute's unit cell

Iron (Fe) crystallizes as a body-centered unit cell with an edge length of 287 pm.What is the atomic radius of iron in picometers?

The $\alpha$ form of polonium (Po) has a density of 9.196 g/cm³ and crystallizes in a simple cubic structure.What is the atomic radius of polonium?

How many nearest neighbor atoms are there around each atom in a face-centered cubic unit cell?

Which of the following statements regarding band theory and solid-state bonding in lithium is NOT correct?

Which of the following refers to an alloy in which the composition of the elements is constant?

Light-emitting diodes contain semiconductors that emit light when a current is passed through them.What is the key factor in determining the wavelength of the emitted light in an LED?

Naphthalene is a white solid that melts at 80.3 $\degree$ C and tends to undergo sublimation at room temperature and pressure.What type of solid is napthalene? Is it an amorphous or crystalline solid?

If half of the tetrahedral holes in a face-centered cubic unit cell are filled, what must be the stoichiometry of the ionic compound, written as nonhole sites:hole sites in lowest terms?

In a simple cubic cell there is/are atoms), in a face-centered cubic cell there is/are_____ atom(s), and in a body-centered cubic cell there is/are ____atom(s).

Which of the following is true regarding the attractive force that holds sodium chloride in the solid state? I.It is electrostatic in nature. II.It is termed ionic bonding. III.It varies with distance between the sodium and chloride. IV.It operates only between adjacent sodium and chloride atoms.

Firing of a kaolinite clay object to make a ceramic results in

If a face-centered cubic unit cell has a volume of 1.980 × 10⁸ pm³ and the atoms at the corners touch the atom on the face, what must be the atom's radius in picometers?

What is the likely unit cell for ionic compounds of 1:1 stoichiometry in which the difference in the radii is only about 25% or less?

A bronze alloy is composed of 10% tin( r = 140 pm) and 90% copper( r =128 pm).It can be classified as

Aluminum (Al) crystallizes as a face-centered unit cell with an edge length of 405 pm.What is the atomic radius of aluminum in picometers?

In a two-component alloy, the more abundant metal can be thought of as the solvent while the less abundant metal can be thought of as the solute.Which of the following is an explanation of why an alloy is often harder than either of the pure elements? I.In a homogenous substitutional alloy, the solute atoms slightly distort the crystal structure, making it hard for atoms to slip past one another. II.In a heterogeneous alloy, small regions rich in the solute atom can disrupt the crystal lattice, making it hard for atoms to slip past one another. III.When solute atoms occupy interstitial sites, they can prevent the atoms in the crystal structure from slipping past one another.

A face-centered cubic unit cell has a(n)____ in its center.

Which of the following statements regarding crystalline solids is NOT correct?

In ionic solids, one ion often occupies a hole in the unit cell defined by the other ion.In a face-centered cubic cell, what are the types and numbers of each hole?