Question 1

The scattering of light waves upon passing through a narrow slit is called ________.

Accepted Answer

The scattering of light waves upon passing through a narrow slit is called diffraction. Diffraction occurs when waves encounter an obstacle or a slit that is comparable in size to their wavelength.

Question 2

The unit cell with all sides the same length and all angles equal to 90° that has lattice points only at the corners is called ________.

Accepted Answer

The unit cell described fits the definition of a primitive cubic unit cell, which has lattice points only at the corners and all sides and angles equal. The other options (monoclinic, body-centered cubic, face-centered cubic) have different types of lattice point arrangements and/or unequal angles. Spherical cubic is not a recognized term in crystallography.

Question 3

Which property of metals cannot be explained with the electron-sea model?

Accepted Answer

The electron-sea model explains properties like conductivity and malleability but does not account for trends in melting points, which are influenced by other factors such as atomic structure and bonding strength.

Question 4

For a substitutional alloy to form, the two metals combined must have similar

Accepted Answer

Substitutional alloys form when the atoms of one metal replace atoms of another metal in the crystal lattice of the base metal. For this to occur, the two metals must have similar atomic radii and chemical bonding properties. The other choices are not necessarily indicative of compatibility for substitutional alloy formation.

Question 5

Heterogeneous alloys

Accepted Answer

The answer of Heterogeneous alloys
...

Question 6

An alloy is a

Accepted Answer

An alloy is a metallic material that is composed of two or more elements. These elements can be metals, nonmetals, or both. Alloys are homogeneous mixtures, meaning that their composition is uniform throughout.

Question 7

Which of the following is not a type of solid?

Accepted Answer

The other four choices are all types of solids that can be classified based on their bonding characteristics, while supercritical is a state that occurs above the critical temperature and pressure of a substance, where it exhibits properties of both a gas and a liquid, but cannot be classified as a solid.

Question 8

Which one of the following is a property of most metals?

Accepted Answer

Most metals have high thermal conductivity, meaning they are able to conduct heat well. This is due to the fact that metals have a "sea" of free electrons that are able to transfer heat energy throughout the material.

Question 9

Crystalline solids differ from amorphous solids in that crystalline solids have ________.

Accepted Answer

Crystalline solids have a long-range repeating pattern of atoms, molecules, or ions, while amorphous solids lack this ordered arrangement. The other options do not accurately describe the difference between crystalline and amorphous solids.

Question 10

Which element is typically not added to steel to modify its properties?

Accepted Answer

Nitrogen is typically not added to steel to modify its properties. Carbon, vanadium, chromium, and nickel are commonly added to steel for various purposes such as increasing strength, improving corrosion resistance, and enhancing ductility.

Question 11

Metallic solids do not exhibit ________.

Accepted Answer

Metallic solids are typically ductile and malleable, meaning they can be hammered or stretched into different shapes without breaking. Therefore, they do not exhibit extreme brittleness.

Question 12

What portion of the volume of each atom or ion on the face of a unit cell is actually within the unit cell?

Accepted Answer

The answer of What portion of the volume of each...

Question 13

Consider the following statements about crystalline solids: (i)Molecules or atoms in molecular solids are held together via
Intermolecular forces.
(ii)Metallic solids have atoms in the points of the crystal lattice.
(iii)Ionic solids have formula units in the point of the crystal lattice.
(iv)Atoms in covalent-network solids are connected via a network
Of covalent bonds.
Which of the statements is false?

Accepted Answer

Ionic solids have ions in the points of the crystal lattice, not formula units. Therefore, statement (iii) is false.

Question 14

Intermetallic compounds are examples of

Accepted Answer

Intermetallic compounds are homogeneous alloys with a definite stoichiometry and ordered crystal structure.

Question 15

A solid has a very high melting point, great hardness, and poor electrical conduction. This is a(n)________ solid.

Accepted Answer

The high melting point and great hardness indicate a strong bond between the atoms, which is characteristic of covalent network solids. The poor electrical conduction also suggests that the electrons are not free to move, which is the case in covalent network solids. Ionic solids typically have good electrical conduction, while metallic solids have good electrical conduction and lower melting points. Molecular solids have lower melting points and are generally softer than covalent network solids.

Question 16

Which one of the following cannot form a solid with a lattice based on the sodium chloride structure?

Accepted Answer

CuCl cannot form a lattice based on the sodium chloride structure because both Cu+ and Cl- ions are of significantly different sizes and do not have the correct size ratio to form such a lattice.

Question 17

What is the typical effect of the addition of an interstitial element on the properties of a metal?

Accepted Answer

The addition of an interstitial element typically leads to an increase in hardness and strength due to the distortion of the crystal lattice caused by the smaller interstitial atom. This can also result in a decrease in ductility. Malleability may or may not be affected depending on the specific interstitial element and its concentration in the metal. Corrosion resistance, melting point, conductivity, and brittleness are not directly related to the addition of an interstitial element. Increased surface luster is also not a typical effect.

Question 18

What fraction of the volume of each corner atom is actually within the volume of a face-centered cubic unit cell?

Accepted Answer

Each corner atom of a face-centered cubic unit cell is shared between eight adjacent unit cells, meaning each corner atom contributes 1/8 of its volume to the volume of a single unit cell. Therefore, the fraction of the corner atom's volume within the volume of a face-centered cubic unit cell is 1/8.

Question 19

Alloys generally differ from compounds in that

Accepted Answer

Alloys are mixtures of two or more metals, or a metal and a non-metal, where the atomic ratios of the constituent elements can vary widely. In contrast, compounds are made up of two or more elements in a fixed, definite proportion. The other options are incorrect; not all alloys contain carbon, iron or transition elements, and not all alloys have semiconductor properties.

Question 20

Which statement about steel is false?

Accepted Answer

The statement that steel is a polymer is false. Steel is not a polymer, but rather an alloy consisting mostly of iron and carbon, as well as small amounts of other elements.

Quiz 12: Solids and Modern Materials