PLTW Properties of Solids

This type of solid forms a regular repeating

three-dimensional structure called a crystal lattice. What type of solid is this?

• amorphous

• crystalline

• glass

• diamond

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

• true

• false

Which of the following is not true about crystalline solids?

• Have a sharp melting point

• Crystalline solids are anisotropic in nature

• Cannot be cleaved along a definite plane

• They are considered as true solids

Which of the following is true of solids?

• Solids maintain a defined shape and size under all conditions.

• All solids have a crystalline structure.

• All solids maintain a defined shape and size if conditions remain constant.

• All solids have a lattice structure at the atomic level.

One major difference between crystalline and amorphous solids is that

• crystalline solids have a precise melting point.

• amorphous solids have a lattice structure.

• amorphous solids always behave consistently and uniformly.

• crystalline solids break unpredictably and can produce curved fragments.

Which type of solid has mobile electrons in the crystal (sea of electrons)?

• Ionic

• Molecular

• Metallic

• Covalent Network

Which type of solid typically has the lowest melting point of the four types of crystals?

• Ionic

• Molecular

• Metallic

• Covalent Network

Which is an example of an ionic crystal?

• Quartz

• NaCl

• Ammonia

• Iron

Which is an example of a metallic crystal?

• Quartz

• NaCl

• Ammonia

• Iron

A friend in your chemistry class is struggling to understand why crystalline solids are grouped into four main types: network, molecular, ionic, and metallic. Which explanation below will BEST help him begin to understand why chemists might have these groups?

• Crystalline solids all share a lattice structure, but have different densities. Chemists use the groups to organize the solids by density.

• Crystalline solids all share a lattice structure and the same types of bonds, but are composed of different elements. These elements affect the way the solid conducts heat and electricity.

• Crystalline solids all share a lattice structure, but behave differently under similar conditions.

• Crystalline solids all share a lattice structure, but the bonds that hold them together at the atomic level differ. The elements that make up the solids also differ. These differences affect how a solid conducts heat and electricity.