States of Matter

The amount of movement within a substance:

Depends on the state of matter of the substance

Which of the following statements is true?

Freezing is the transition of a liquid to solid

Which of the following terms best describes a sample composed of particles that can be squeezed together?

Gas -particles in gases are far apart and move about very quickly. The particles have much more energy and this is why they move so fast. The particles collide with each other and the walls of the container filling the volume of the container. A gas can be easily compressed because of the space between the particles. -The particles in a solid are tightly packed and locked in place. Although we cannot see it or feel it, the particles are moving - vibrating in place. -The particles in a liquid are close together but they are able to move, slide or flow past each other.

Which of the following descriptions is correct?

Gas: no definite volume and no definite shape

Movement of molecules in a substance depends on _______ energy.

Heat -Heat is a form of energy that is created through the movement of atoms and molecules.

Which of the following definitions is correct?

Liquids have a constant volume but not a constant shape.

Why are gases compressible whereas solids are not compressible?

Particles in a gas have a large amount of empty space between them. -The atoms and molecules in gases are much more spread out than in solids or liquids. They vibrate and move freely at high speeds. A gas will fill any container, but if the container is not sealed, the gas will escape. Gas can be compressed much more easily than a liquid or solid. -In solids, the atoms or molecules are closely packed together, so they are very dense and are held together by strong intermolecular forces of attraction. When we put pressure on solids, to compress them, there no space between the atoms/molecules and as a result we cannot compress them.

By looking at a phase diagram of water, what can be assessed?

Pressure and temperature are needed to change water from liquid to gas

The direct transition from a solid to a gas may occur through which of the following processes?

Sublimation -Through sublimation, a substance changes from a solid to a gas without ever passing through a liquid phase. Dry ice, solid CO2, provides a common example of sublimation.

Which of the following components can be found in a phase graph?

Temperature and pressure as its axes -The phase diagram is a graphical representation of the physical states of a substance under varying conditions of temperature and pressure. A typical phase diagram has pressure on the y-axis and temperature on the x-axis. They contain a triple point - the point on a phase diagram at which the three states of matter: gas, liquid, and solid coexist; and a critical point - the point on a phase diagram at which you cannot tell the difference between the liquid and gaseous states of the substance.

Which of the following statements correctly describes "deposition"?

The transition of a substance from gas to solid without passing through the liquid state

Which of the following statements correctly describes "sublimation"?

The transition of a substance from solid to gas without passing through the liquid state

Which of the following statements is true?

The triple point of a substance is the temperature and pressure at which three phases of a substance may coexist in thermodynamic equilibrium. -In thermodynamics, the triple point of a substance is the temperature and pressure at which the three phases (gas, liquid, and solid) of that substance coexist in equilibrium.

By looking at a phase diagram of carbon dioxide, what can be assessed?

The triple point of carbon dioxide

Freezing

a phase transition in which a liquid turns into a solid when its temperature is lowered below its freezing point.

Melting is the physical process in which

a solid transitions in a liquid -This happens when the internal energy of the solid increases (usually due to the application of heat or pressure), which in turn increases the substance's temperature up to the melting point.

Gas

a substance with no definite volume and no definite shape. Solids and liquids have volumes that do not change easily.

All matter is made up of particles called

atoms (which make up molecules) -These atoms and molecules are always in motion - bumping into each other or vibrating back and forth.

Liquids

can occupy whatever shape their container has, so they do not have a fixed shape. -Because the particles in liquids are very close together (barely further apart than in solids) liquids do not easily compress, so their volume is fixed.

A phase diagram is a type of chart used to show conditions (pressure, temperature, volume, etc.) at which thermodynamically distinct phases (such as solid, liquid or gaseous states) occur and

coexist at equilibrium.

The critical point on a phase diagram is the end point of a phase

equilibrium curve. -The most common is the liquid-vapor critical point, where you cannot tell the difference between the liquid and gaseous phases.

Solid

has a definite shape and volume. There are two kinds of solids—crystalline and amorphous.

The amount of movement of molecules in a substance

increases as it gains heat and decreases as it loses heat. -At higher temperatures, particles have more energy. Some of this energy can be transmitted to other particles that are at a lower temperature.

Condensation

is the change of the physical state of matter from gas phase into liquid phase, and is the reverse of evaporation (liquid to gas).

Deposition

occurs when a substance goes directly from the gas state to the solid state. -This means it skips over the liquid state, like sublimation (when a substance goes directly from the solid state to the gas state).

In gases, the particles move freely with

rapid, random motion.

In contrast to sublimation, the process of deposition

releases energy -An example of deposition is the formation of frost. In cold temperatures, water vapor undergoes deposition to form a thin layer of solid ice on plants and grass.

The particles in liquids also vibrate but are able to move around by

rolling over each other and sliding around.

Chemical decomposition is the separation of a

single chemical compound into its two or more elemental parts or to simpler compounds.

There are many types of electromagnetic waves. From lowest energy to highest energy there are radio waves, microwaves, infrared, visible light, ultraviolet, x-rays and gamma rays (see diagram below). They do not affect the movement of particles in

substances

Sublimation

the phase change that occurs when a substance goes directly from a solid to a gas. -When sublimation occurs, the substance does not go through the liquid phase. Energy is required for a solid to sublime into a gas. In nature, the heat produced by sunlight is usually the energy source.

The particles in solids are

tightly packed and can only vibrate.