Unit 3: Topic 3 - Solids, Liquids, and Gases

Question 1

What are the characteristics of solids?

Answer 1

Characteristics of Solids:
1) They retain their shape and volume. (Motion of the particles is limited)
2) The strong intermolecular forces are why solids are incompressible and don’t flow.

Solids can be amorphous or crystalline. Here is a visual.
Amorphous solids: The particles are not orderly arranged. Ex: Glass, rubber, and plastics.
Crystalline solids: The particles are arranged in a regularly repeating pattern. The geometric pattern formed by the particles is called a crystal lattice. Ex: Salt and diamond

“When a compound changes phases, intermolecular forces are broken or formed, NOT covalent bonds”

Question 2

What are the characteristics of liquids?

Answer 2

Characteristics of Liquids:
1) Liquids retain their volume but not their shape. Their shape is determined by the container.
2) Intermolecular forces aren’t strong enough to keep their shape but enough to hold themselves together. They are in constant motion and are incompressible but are able to flow.

Question 3

What are the properties of liquids?

Answer 3

Properties of liquids
Surface tension: The tension created at the surface of a liquid. The stronger the IMF, the greater the tension.
Capillary action: The rising of a liquid up a tube due to cohesion (forces between the same molecules) and adhesion (forces between the molecule and a surface). If cohesion forces are stronger than the adhesive, it will form a convex meniscus. If adhesive forces are stronger, then the liquid will form a concave meniscus. Here is a visual.
Viscosity: A fluid’s resistance to flow. The stronger the IMF, the more viscous. (Syrup is more viscous than water since it isn’t able to flow as easily as water)

Question 4

Why does the solid and liquid phase for a particular substance have similar molar volume?

Answer 4

Here is a visual of the particles in solids and liquids compared to gases.
Solids and liquids for a particular substance have similar molar volumes because the distance between two molecules in a solid is similar to those in a liquid molecule. On the other hand, gases lack intermolecular forces, which results in their drastic difference in molar volume from solids and liquids.

Question 5

What are the characteristics of gas?

Answer 5

Characteristics of Gases:
1) Gases don’t retain their shape or volume. Both are determined by the container.
2) There are barely any intermolecular forces. Thus, the particles are able to move freely and constantly. They are compressible and flow.
The frequencies of collision are determined by the temperature, pressure, and volume of the container. More on this in the next topic!

Here is a diagram summarizing the characteristics of solids, liquids, and gases.