1.
The following occurs when heat energy is removed:
Gas ---(A)--> Liquid ---(B)---> Solid
What would be the phase changes for A and B respectfully?
Correct Answer
C. Condensation, Freezing
Explanation
The given diagram shows the phase changes that occur when heat energy is removed. When heat is removed from a gas, it undergoes condensation and changes into a liquid (phase change A). Then, when more heat is removed from the liquid, it undergoes freezing and changes into a solid (phase change B). Therefore, the correct answer is condensation, freezing.
2.
Examine the following sequence of phase changes:
Solid ---> Liquid ---> Gas
Would we need to add or remove heat energy?
Correct Answer
A. Add heat energy
Explanation
In the sequence of phase changes from solid to liquid to gas, heat energy must be added at each step. Adding heat energy causes a solid to melt into a liquid, and further adding heat causes the liquid to evaporate or vaporize into a gas. These processes require the absorption of heat to overcome the intermolecular forces holding the particles together in the solid and liquid states.
3.
When isopropyl alcohol was spilled over the counter top and quickly disappeared, what phase change occurred?
Correct Answer
A. Evaporation
Explanation
When isopropyl alcohol is spilled over the counter top and quickly disappears, it indicates that a phase change of evaporation has occurred. Evaporation is the process in which a liquid turns into a gas at a temperature below its boiling point. In this case, the isopropyl alcohol molecules gained enough energy from the surroundings to escape the liquid state and become a gas, causing it to disappear rapidly.
4.
A student noticed frost was on the ground at 6:30 a.m. but noticed it disappeared by 8:30 a.m. What phase change was responsible for turning the frost into water vapor?
Correct Answer
C. Sublimation
Explanation
The phase change responsible for turning the frost into water vapor is sublimation. Sublimation occurs when a solid directly changes into a gas without going through the liquid phase. In this case, the frost on the ground transformed directly into water vapor without melting into liquid water first.
5.
The phase change that occurs when a gas is cooled and changes into a solid is known as...
Correct Answer
C. Deposition
Explanation
Deposition is the phase change that occurs when a gas is cooled and changes directly into a solid, bypassing the liquid phase. This process involves the conversion of gas molecules into solid particles, resulting in the formation of a solid substance. Unlike freezing, which involves the transition from a liquid to a solid, deposition directly converts a gas into a solid without going through the liquid state.
6.
Which states of matter can be compressed?
Correct Answer
C. Gas
Explanation
Of the three primary states of matter—solid, liquid, and gas—gas is the only state that can be significantly compressed. Gases consist of widely spaced particles that move freely, allowing them to be compressed into smaller volumes. This characteristic makes gases ideal for use in applications like pressurized cylinders, airbags, and compressed air systems.
7.
A ___________ has a definite shape and a definite volume.
Correct Answer
A. Solid
Explanation
A solid has a definite shape and a definite volume because its particles are closely packed together and have strong intermolecular forces. This arrangement prevents the particles from moving freely, resulting in a fixed shape and volume.
8.
A ____________ has no definite shape, but a definite volume.
Correct Answer
B. Liquid
Explanation
A liquid is a substance that does not have a definite shape, meaning it can take the shape of its container. However, it does have a definite volume, meaning it maintains a specific amount of space. Unlike a solid, which has both a definite shape and volume, or a gas, which has neither a definite shape nor volume, a liquid falls in between by having a definite volume but not a definite shape. A molecule, on the other hand, is not the correct answer as it refers to the smallest unit of a substance and does not have the properties of shape or volume.
9.
The change in state from gas to liquid is called ____________.
Correct Answer
A. Condensation
Explanation
Condensation is the correct answer because it refers to the process of a substance changing from a gaseous state to a liquid state. This occurs when the temperature of the gas decreases or when the pressure on the gas increases. During condensation, the gas molecules lose energy and come together to form liquid droplets. This can be seen, for example, when water vapor in the air cools and forms water droplets on a cold surface.
10.
The molecules in a solid vibrate against each other.
Correct Answer
A. True
Explanation
In a solid, the molecules are tightly packed and held together by strong forces of attraction. These forces cause the molecules to vibrate in place. This vibration is known as thermal motion and is responsible for the solid's rigidity. Therefore, the statement that the molecules in a solid vibrate against each other is true.
11.
Check any of the following that are part of the Kinetic Theory:
Correct Answer(s)
A. All particles are in constant, random motion
C. Particles are constantly colliding with each other due to their constant motion.
D. All matter is made of small particles like atoms and molecules.
Explanation
The Kinetic Theory states that all particles are in constant, random motion. This means that particles are constantly moving and changing direction. Additionally, particles are constantly colliding with each other due to their constant motion. This collision between particles is what gives rise to pressure in gases. Finally, the Kinetic Theory also states that all matter is made of small particles like atoms and molecules. These particles are constantly moving and interacting with each other, leading to the observable properties of matter.
12.
In order for a liquid to change into a solid, the object must ______________ thermal energy.
Correct Answer
B. Lose
Explanation
When a liquid loses thermal energy, its temperature decreases, causing the particles to move more slowly and come closer together. This process eventually leads to solidification or freezing, where the liquid turns into a solid state. This loss of thermal energy is essential for the phase transition from liquid to solid.
13.
Matter
changes state when a sufficient amount of thermal energy changes.
Correct Answer
A. True
Explanation
Matter changes state when the amount of thermal energy
increases or decreases.
14.
Matter is
anything that has mass and takes up space.
Correct Answer
A. True
Explanation
Matter refers to any substance that has mass and occupies space. This definition encompasses all physical objects, including both living and non-living things. Therefore, the statement that matter is anything that has mass and takes up space is true.
15.
Evaporation
takes place throughout the entire liquid.
Correct Answer
B. False
Explanation
Evaporation is a physical change from a LIQUID to a GAS and only occurs at the surface of the liquid.
16.
What phase
change does dry ice undergo when it transforms from a solid to a gas,
skipping the liquid phase entirely?
Correct Answer
C. Sublimation
Explanation
Sublimation is a physical change from a SOLID to a GAS. The solids do not pass through liquid phase; they immediately transform into a gas.
17.
When you
place a pot of water on the stove and heat the water up, you notice that
bubbles form throughout. What phase change is the water undergoing?
Correct Answer
A. Boiling
Explanation
Boiling is a physical change from a LIQUID to a GAS. It takes place throughout the liquid (surface and below).
18.
What happens to the speed in which particles move when the change from a liquid to a solid?
Correct Answer
B. Particles speed decreases
Explanation
When an object changes from a liquid to a solid, the object loses thermal energy, therefore the particles begin to move slower and slower until the object changes phases.
19.
The temperature at which matter changes from a solid to a liquid is called the _________ point.
Correct Answer
B. Melting
Explanation
The correct answer is "melting" because it refers to the temperature at which a substance changes its state from a solid to a liquid. This process involves the breaking of intermolecular forces holding the particles in a fixed position, allowing them to move more freely and take the shape of the container.
20.
The beads of sweat on the outside of your cup come from the water vapor in the air. What phase change did the water vapor have to undergo to become the dew drops on the outside of your cup?
Correct Answer
B. Condensation
Explanation
Condensation occurs when water vapor loses thermal energy and condenses into liquid.