Exam 18: The Solid State a Particulate View

According to band theory, when the lower-energy ____band is separated from the higher-energy____ band by a small band gap, the material will act as a(n) ____of electricity.

In the sodium chloride unit cell, the chloride ions form a cube in which each side is arranged as in the following figure.The circles represent the positions of the chloride ions on one square face of the cube.All the other faces are the same.What is the name of this unit cell?

Which of the following contributes) to the arrangement of ions in the unit cells of an ionic solid? I.the empirical formula II.the relative radii of the ions III.the shape of polyatomic ions

In addition to carbon and iron, stainless steel contains

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

What is the probable origin of the electrical conductivity of cadmium when its electron configuration is [Kr]4d ¹⁰5s²?

When a small amount of silver is added to zinc sulfide as an activator, the band gap of the resulting material is approximately 266 kJ/mol.If this material were used as a light-emitting diode, what color of light would be emitted?

Aluminum (Al) has a density of 2.70 g/cm³ and crystallizes in a face-centered cubic structure.What is the unit cell edge length?

An unknown metal with an fcc structure has a density of 10.5 g/cm³, and the edge length of the unit cell is 409 pm.What is the probable identity of the metal?

Magnesium oxide adopts a rock salt structure with a density of approximately 3.58 g/cm³.Based on this information, calculate an estimate of the unit cell edge length in picometers.

Consider the three unit cells below for ionic solids.In each unit cell, one of the ions is arranged in one of the standard unit cell structures while the other is found between these sites.What are the names of the minerals associated with each of these structures? I _____; II_____ ; III_____ .

A ceramic is a chemically resistant and heat-resistant solid produced by heating

Cesium bromide adopts a cubic structure in which bromide ions lie at the corners of the cube with the cesium ions lying in the holes in the center of the cubes.The density of CsBr is 4.44 g/cm³.Calculate the approximate edge length of the unit cell in picometers.

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

Gold (Au) has a face-centered cubic structure with a unit cell edge length of 407.8 pm.What is the calculated value of the density of gold based on this information?

Fragments of a linear allotrope of carbon were first prepared and characterized in 1998.Would you expect this form of carbon to conduct electricity?

An approximately spherical allotrope of carbon containing 60 or 70 atoms is

When germanium (Ge) is doped with gallium (Ga), it produces a(n)______ -type semiconductor.

Describe the ccp and hcp crystal structures.Include the arrangement of atoms in one layer as well as how layers are stacked to form the crystal lattice.

How many tennis balls will fit within the interstitial holes between a truckload of basketballs perfectly placed in a closest-packed arrangement? Assume that the tennis balls have a radius that is 20% that of a basketball.