eQuizShow

Kinetic Molecular Theory

States of Matter

Question: On your white board, draw 3 pictures, One showing particles in a SOLID, one showing particles in a LIQUID, and one showing particles in a GAS.
Answer: Solid: Particles all lined up and touching. Solid has a square/recatngular shape
Liquid: Particles are not lined up, and can either be touching or have some space between them. Liquid takes the shape the container.
Gas: Particles are spread out and are not touching. Gas takes shape of container.


Question: Name the phase(s) of matter in which there is cohesion between the particles.


Answer: solid and liquid
(there is no cohesion between gas particles)

Question: Which state(s) of matter can be compressed? Explain why the state(s) cannot be compressed.
Answer: Only a gas can be compressed because there is space between the particles. Particles in a liquid and a solid are too close together.

Question: In which state(s) of matter can particles change their positions with other particles?
Answer: liquid and gas

Question: What would happen to a birthday balloon taken outside on a VERY cold day? Why does this happen?
Answer: The balloon would get smaller because the particles would slow down and contract (get closer together).

Phase Change

Question: If the freezing point of alcohol is -115 degrees C, what is the melting point of alcohol?
Answer: -115 degrees C

Question: Are the following phase changes exothermic or endothermic:

condensation, freezing, deposition
Answer: exothermic (heat is exiting)

Question: The melting point of a substance is the __________________ at which a substance changes from a ______________ to a _______________.
Answer: ...is the TEMPERATURE at which a substance changes from a SOLID to a LIQUID.

Question: What happens to the temperature and kinetic energy when a substance changes states from
Solid to a Liquid to a Gas
Answer: KE and Temperature increase

Question: Explain how evaporation lowers the temperature of the liquid that is evaporating. Use the word "particle' in your answer.
Answer: During evaporation, faster moving particles near the surface of the liquid pop free of the liquid and change to a gas. The liquid then contains only the slower moving particles, which are cooler.

Vocabulary

Question: Define the following word: EXPANSION
Answer: When particles spread out due to warm temperatures.

Question: Define: INFERENCE
Answer: An educated guess, OR a conclusion drawn from observations that explains the observations

Question: Define DIFFUSION
Answer: The intermingling or mixing of particles from areas of high concentration to low concentration.

Question: Compare and Contrast Adhesion and Cohesion

(For contrasting: you can define the two terms. For comparing, you can state one thing that they have in common)
Answer: Compare:
Both have to do with attraction between particles
Contrast:
Adhesion is the attraction between UNLIKE particles
Cohesion is the attraction between LIKE particles

Question: Compare and Contrast Heat and Temperature

(For contrasting: you can define the two terms. For comparing, you can state one thing that they have in common)
Answer: Compare:
Both have to do with Energy of particles
Contrast:
Temperature is the AVERAGE kinetic energy of a the particles in a substance
Heat is the TOTAL energy of the molecules in a substance


Heat Transfer

Question: Name the three types of heat transfer.
Answer: Conduction, Convection, and Radiation

Question: Look at the diagram A on the board. Heat will move from the ____________ to the ___________.
Answer: From the water in the beaker to the test tube.

Question: True or False. If false, how would you correct it.

Your warm jacket keeps you from absorbing cold from the air.
Answer: False: Your warm jacket keeps the air from absorbing heat from you.

Question: Use the Kinetic Theory of Motion to explain why heat transfer by convection cannot happen in a solid
Answer: In convection, warmer particles rise and cooler particles sink, but in a solid the particles cannot move apart.

Question: Diagram C shows how the temperature of a hot cup of tea and a glass of ice water change over time. Why does heat transfer eventually stop?
Answer: The hot tea and ice water eventually reach thermal equilibrium, and are at room temperature.

Miscellaneous

Question: Which has a higher average kinetic energy - the ocean or a cup of hot tea?
Answer: cup of hot tea
(Average kinetic energy = temperature)

Question: Diagram B on the board shows water cooling from 150 degrees C to -20 degrees C. Which letter indicates where the water is in a gas phase.
Answer: A

Question: Diagram B on the board shows water cooling from 150 degrees C to -20 degrees C. What is happening at segment D on the graph?
Answer: Freezing (liquid to solid)

Question: Diagram B on the board shows water cooling from 150 degrees C to -20 degrees C. What is happening in segment B? AND explain why the graph looks as it does.
Answer: Condensation is occurring (gas changing to liquid liquid). The temperature stays the same during a phase change until all the particles of the substance have changed.

Question: How does heating an object affect its volume?
Answer: Heating increases speed of particles, so they move farther apart. Thus, volume INCREASES.