Chapter 2: Changes in Matter

Describe the particles of a gas.

A gas can change volume very easily. Also, gas particles spread apart, filling all the space available to them.

What is a gas?

A gas has neither definite shape nor volume.

What is a graph?

A graph is a diagram that tells how two variables are related.

What is a liquid?

A liquid has no definite shape but does have a definite volume.

What is a physical change? What are some examples? What substance does it change to?

A physical change alters the form of a substance, but does not change it to another substance. Some examples of a physical change are melting,freezing, tearing, crumpling. During a physical change it remains the same substance.

What is an example boiling?

A pot of water on a stove reaches its boiling point

What is an example evaporation?

A puddle dries up after a rain shower

What is boiling point?

A pure substance boils only at a certain temperature, which is called its boiling point.

Which state of matter has a definite volume and a definite shape?

A solid has a definite volume and a definite shape.

What is a fluid?

A substance that flows is called a fluid.

What are amorphous solids? What are some examples?

An amorphous solid's particles are not arranged in a regular pattern. Examples include plastic, rubber and glass.

What is an example condensation?

Clouds form from water vapor in the sky

What is condensation?

Condensation occurs when a gas loses enough thermal energy to become a liquid.

Why are crystalline solids? What are some examples?

Crystalline solids are made up of crystals and are arranged in a regular pattern. Examples include salt sugar, sand, and snow.

Give an example of sublimation.

Dry ice is an example of sublimation. Dry ice is a solid and when it melts it turns into carbon dioxide.

What is sublimation?

During sublimation, particles of a solid don't pass through the liquid state as they form a gas.

List three things that each axis of a graph is labeled with.

Each axis is labeled with the name of the variable, the unit of measurement ,and a range of values.

What are the two main types of vaporization? When does each take place?

Evaporation is one. It takes place ONLY ON THE SURFACE OF A LIQUID. Boiling is the second one. It takes place INSIDE A LIQUID AS WELL AS AT THE SURFACE.

The faster gas particles are moving, the greater their energy and the lower the temperature.

False

What is freezing?

Freezing is the change in state from a liquid to a solid.

If the temperature of a gas is decreased at constant pressure, what happens to its volume?

If the temperature of a gas is decreases at constant pressure, the volume decreases.`

If the temperature of that gas in the container is decreased, what happens to its pressure?

If the temperature of that gas in the container is decreased, the pressure also decreases.

Suppose a gas is kept in a closed, rigid container. If the temperature of the gas is increased, what happens to its pressure on the container?

If the temperature of the gas is increased, the pressure also increases in the container.

In a flexible container, raising the temperature of a gas does what it its volume?

In a flexible container, raising the temperature of a gas increases its volume.

What is the melting point?

In most pure substances, melting occurs at a specific temperature called the melting point.

What is an example of vaporization?

Liquid water changes into water vapor

Do liquids with high or low viscosity flow quickly?

Liquids with high viscosity flow SLOWLY. Liquids with low viscosity flow QUICKLY.

When does matter change?

Matter changes whenever energy is added or taken away.

What is melting?

Melting is the change in state from a solid to a liquid.

At its freezing point, the particles of a solid are vibrating so fast that they break free from their fixed positions. Is this true?

No, it is completely false. Remember, the particles of a solid are packed tightly together.

What can cause tires to burst on long trips in warm weather?

On long trips a truck's tires can get very hot. As the temperature increases so does the pressure of the air inside the tire. If the pressure becomes higher than the tire can hold the tire will burst.

What is the formula for Pressure?

Pressure = Force divided by area

What does Boyle's law say about the relationship between the pressure and volume of a gas?

Pressure decreases- Volume increases Volume decreases - Pressure increases

What is pressure?

Pressure is the force pushing on a surface divided by the area of that surface.

What is the principle known as Charles's law?

Temperature increases- volume increases Temperature decreases- volume decreases

What is temperature?

Temperature is a measure of the average energy of motion of particles of a substance.

What is the y axis and what is the x axis?

The VERTICAL axis is known as the y axis. The HORIZONTAL axis is know as the x axis.

If you put a gas into a container with a top, what will the gas do?

The gas will fill the container and move around rapidly until the lid is removed.

What does the graph for Boyle's law show about the relationship between the pressure and volume of a gas?

The graph for Boyle's law shows that the pressure of a gas varies inversely with its volume.

Why is the boiling point of water lower on top of a mountain than it is at sea level?

The lower the air pressure above the liquid, the less energy the liquid molecules need to escape into the air. As you go up in elevation. air pressure decreases.

What is the melting temperature of a crystalline solid?

The melting point of a crystalline solid is specific.

What is the melting temperature of a amorphous solid?

The melting temperature of an amorphous solid doesn't have a distinct melting point. Instead, when heated an amorphous solid becomes softer and softer as its temperature rises

Describe the particles of a liquid.

The particles of a liquid move around one another freely.

Describe the particles of a solid.

The particles of a solid: -stay in about the same position and - vibrate back and forth.

What is the point (0,0) on a graph called?

The point (0,0) on a graph is called the origin.

What is a chemical reaction?

The term chemical reaction is another name for a chemical change.

What variable does the x axis show?

The x axis shows the manipulated variable.

What variable does the y axis show?

The y axis shows the responding variable.

List three measurements that are helpful to know when working with a gas.

Three measurements that are helpful to know when working with a gas are volume, temperature, and pressure.

What is vaporization?

Vaporization is the change from a liquid to a gas.

When does vaporization take place?

Vaporization occurs when a liquid gains enough energy to become a gas.

What is viscosity?

Viscosity is the resistance of a liquid to flowing.

When a graph of two variables forms a curve that slopes downward from left to right, the variables are said to be what?

When a graph of two variables forms a curve that slopes downward from left to right, the variables are said to vary inversely with one another.

When a graph of two variables is a straight line passing through the origin, the variable are said to be what?

When a graph of two variables is a straight line passing through the origin, the variable are said to be directly proportional.

What is a chemical change? What are some examples? What substance does it change to?

When a substance undergoes a chemical change, it is changed into a different substance with different properties. Some examples of a chemical change are cooking, burning, combustion, rust, decomposing, and photosynthesis. Also water (2H + O = H2O). During a chemical change it changes to a new substance.

When condensation occurs, does a gas lose or gain thermal energy?

When condensation occurs, a gas loses thermal energy.

What happens to the pressure when the temperature of a gas is increased?

When the temperature of a gas is increased, the pressure of the gas increases.

Is condensation the opposite of vaporization?

Yes

Will a solid keep its volume and its shape in any position and in any container? Why?

Yes, because the particles in a solid are packed tightly together and in a fixed position.

Is a gas a fluid?

Yes, like a liquid, a gas is a fluid.

The volume of a gas is the same as the volume of its

container.