Types of Solid

Which of the following could be the identity of a white crystalline solid that exhibits the following properties?

-It melts at 320°C.

-It does not conduct electricity as a solid.

-It conducts electricity in an aqueous solution.

• C₆H₁₂O₆(s)

• NaOH(s)

• SiO₂(s)

• Cu(s)

In solid methane, the forces between neighboring CH₄ molecules are best characterized as

• ionic bonds

• covalent bonds

• hydrogen bonds

• ion-dipole forces

• London (dispersion) forces

A sample of a hard, solid binary compound at room temperature did not conduct electricity as a pure solid but became highly conductive when dissolved in water. Which of the following types of interactions is most likely found between the particles in the substance?

• Ionic bonds

• Metallic bonds

• Covalent bonds

• Hydrogen bonds

In amorphous solids, the atoms or molecules are held together in a completely random formation.

• true

• false

A certain crystalline substance that has a low melting point does not conduct electricity in solution or when melted. This substance is likely to be

• a covalent network solid

• a metallic solid

• a polymer

• an ionic solid

• a molecular solid

A student is given a sample of a pure, white crystalline substance. Which of the following would be most useful in providing data to determine if the substance is an ionic compound?

• Examining the crystals of the substance under a microscope

• Determining the density of the substance

• Testing the electrical conductivity of the crystals

• Testing the electrical conductivity of an aqueous solution of the substance

The structure of one form of boron nitride is represented above. This form of boron nitride is one of the hardest substances known. Which of the following best helps explain why boron nitride is so hard?

• Boron ions and nitrogen ions are held together by ionic bonds.

• Boron nitride is a network solid of atoms connected by covalent bonds with fixed bond angles.

• Boron nitride is an alloy, and alloys are typically harder than the elements used to make them.

• Boron nitride is a polymer made of long chains of boron atoms and nitrogen atoms held together by dispersion forces.

Three substances were studied in the laboratory, and the data in the table above were collected. Based on the data, which of the following shows the type of bonding in each substance?

• Substance X: Network covalent; Substance Y: Ionic; Substance Z: Metallic

• Substance X: Ionic; Substance Y: Molecular; Substance Z: Network covalent

• Substance X: Molecular; Substance Y: Network covalent; Substance Z: Metallic

• Substance X: Network covalent; Substance Y: Metallic; Substance Z: Ionic