What is happening to water molecules in the air where it meets the lid of the cup? Explain your reasoning.
Question 21
21.
Why can'twater from the inside leak through the walls of the cup? Explain your reasoning.
Question 22
22.
What is the difference between a closed system and an open system? Explain your reasoning.
Question 23
23.
Think about times you have gotten a hot drink. What are some strategies cup designers have used to maintain the temperature for longer times? Explain your reasoning.
Which state of matter has particles that are tightly packed together?
Liquid
Gas
Solid
Which statement is true about gas particles?
They are always in a fixed shape.
They are all touching each other.
They have a lot of space between them.
Which state of matter takes the shape of its container?
Solid
Gas
Liquid
What is happening to the liquid water that can explain why the mass of the cup system deceases over time?
The water molecules evaporate, leaving the system and reducing mass.
The water molecules bond with air particles, doubling the mass.
The water turns into gas and increases the mass of the system.
What is a practical wa to measure if mass is lost from the cup systems during the experiement?
By weighing the cups before and after the experiement
By using a thermometer to check the lid's humidity
By observing the color change of the water
When discussing other methods to determine if the water amount decreases without a scale, which method is most reliable?
Observing the water level over time using a marked container
Smelling the water to see if it becomes stronger
Shaking the container to feel for weight changes
If we completely sealed off the cup so no matter could get in or out, why would the temperature of the liquid inside still change?
The liquid would create internal pressure forcing temperature change.
The seal would cause the liquid to gain mass, changing temperature.
Heat transfer still occurs through the cup walls, influencing temperature over time.
How could time-lapse or slow-motion videos help if you didn't have a scale for measuring mass?
They automatically calculate the data for you, reducing human error.
They can visually show changes in the water level over time, indicating mass loss.
They help to capture the temperature changes in the liquid correctly.
Why do droplets form on the outside of a cold pitcher?
Because droplets escape from ice cubes in the pitcher
Because lemonade leaks through the pitcher
Because water vapor in the air condenses on the cold surface
What should you conclude if the colored water inside does not change the color of the droplets outside?
The cup absorbs the food coloring.
Water outside is from the air, not the cup content.
Water inside the cup is evaporating too quickly.
Which experiment setup best confirms the source of the water droplets on the outside of a cup?
Covering the cup with plastic wrap
Heating the cup and observing droplets
Adding food coloring to the water inside the cup
How can the structure of solid particles explain why water cannot leak through the walls of the cup?
Solid particles are tightly packed, preventing leakage.
Solid particles dissolve when in contact with water.
Solid particles vibrate and create gaps for water to pass.
Why is it important that the mass of the cups was measured immediately after adding the cold water?
To confirm the water's temperature inside the cups
To ensure accurate baseline measurements before any condensation forms
To see if the lids prevent immediate mass change
What conclusion can be drawn from seeing droplets form on an empty chilled cup?
New moisture forms directly on the empty cup.
Air particles solidify upon touching the chilled cup.
Condensation is the source of water droplets in the observational setup.
Which cup do you think warmed up more after 10 minutes? Why?
The cup with the old lid because it's a closed system.
The cup with the new lid because it allows more heat to escape.
The cup with the new lid because it keeps heat in better.
In what units was the temperature of the water measured?
Kelvin
Liters
Degrees Celsius
What happens to the water particles in the cup with the new lid compared to the old lid?
More water particles leave the system through the larger opening.
The water particles grow larger.
The water particles stay more still.
Imagine we could zoom in to a point where the liquid meets the wall of the cup. What do we think is happening to water molecules there?
The molecules bounce off the cup wall and stay in the liquid.
The molecules are absorbed by the wall of the cup.
The molecules pass through the wall.
How does this model help you visualize why water molecules can move freely between other water molecules but can't go through the particles the plastic cup wall is made of?
It shows that the particles in the plastic are closely packed.
It demonstrates the temperature efffects on water.