Lesson 4: OpenSciEd 6.2 Thermal Energy

Why does adding a lid help decrease the amount of water leaving the system?

• A lid prevents water molecules from escaping as vapor.

• A lid traps all the air inside the system.

• A lid makes the system heavier.

• A lid changes the chemical composition of the water.

Why does adding a lid help decrease the amount that the water temperature changes?

• A lid helps insulate the system, keeping the heat in or out.

• A lid introduces cold or hot air into the system.

• A lid increases water evaporation.

• A lid allows sunlight to reach the water.

What would happen to the temperature of hot water in a cup without a lid compared to a cup with a lid?

• The cup without a lid would cool down faster.

• The cup without a lid would maintain its temperature.

• Both cups would cool down at the same rate.

• The cup with a lid would cool down faster.

What is a practical way to measure if mass is lost from the cup systems during the experiment?

• By weighing the cups before and after the experiment

• By checking the temperature regularly

• By observing the color change of the water

• By using a thermometer to check the lid’s humidity

Based on the data, what conclusion can you draw about the effectiveness of a lid in reducing temperature change of hot water?

• A cup with a lid causes a hot liquid in the cup to drop in temperature less than in a cup without a lid.

• A cup with a lid causes a hot liquid in the cup to drop in temperature more than in a cup without a lid.

• A cup with a lid causes the same temperature change as a cup without a lid.

• A cup with a lid causes an unpredictable change in temperature compared to a cup without a lid.

After reviewing the average temperature changes, why is it beneficial to use the average rather than individual data points for comparison?

• It simplifies the data by providing a single value representing the overall trend, reducing variability.

• It eliminates the need for detailed analysis of each data point.

• It hides any possible errors in measurements.

• It makes the data look more consistent than it actually is.

How does weighing each system at the start and end of the experiment provide insights into what happens to the water?

• It helps determine if any mass is lost, indicating evaporation or condensation.

• It ensures that the water was initially pure.

• It confirms the temperature changes measured.

• It verifies that the experiment was conducted properly.

Why is it important to develop a model to explain why the mass of the cup system decreases over time?

• A model helps visualize and understand the process of evaporation and condensation.

• It serves as a physical representation of the data table.

• It allows for different types of experiments to be conducted.

• It makes the experiment look more scientific.

How does adding a lid help decrease the amount of water leaving the system?

• The lid reduces exposure to air, slowing down evaporation.

• The lid increases the pressure inside the cup.

• The lid causes the water to boil.

• The lid prevents the water from heating up.

When water evaporates from the cup system, what is the most logical explanation for where the lost mass goes?

• The water molecules evaporate into the air, reducing the mass of the liquid left in the cup.

• The mass converts into energy.