Thermal Energy Study Guide 6th 22-23

A fisherman in a boat is drinking a cup of hot coffee. The large lake below his boat is full of cold water. Which statement is an accurate comparison of the lake water and the coffee?

• The lake will have more total thermal energy, and the particles in the lake water will be moving faster.

• The coffee will have more total thermal energy, and the particles in the coffee will be moving faster.

• The coffee will have more total thermal energy, but the particles in the lake water will be moving faster.

• The lake will have more total thermal energy, but the particles in the coffee will be moving faster.

Use the image to answer the question.

The gallium in the image is melting in the person’s hand. Which changes will occur on a microscopic level? 

• The gallium atoms will gain potential energy, moving freely from each other.

• The gallium atoms will increase in temperature.

• The gallium atoms will be moving faster on average.

• The gallium atoms will gain kinetic energy.

Which object will have particles with the highest average kinetic energy?

• water at 40°C in a swimming pool

• a drop of water at 90°C

• an iceberg at 0°C

• water at 37°C in a glass

Thermal energy is transferred to a substance. Which change can occur?

• The particles can gain potential and kinetic energy.

• The particles can gain kinetic energy, but the potential energy of the particles will stay the same.

• The particles will gain potential energy, but the kinetic energy of the particles will stay the same.

• The kinetic and potential energy of the particles will stay the same. 

Which option is a measure of the average kinetic energy of the particles in a substance?

• thermal energy

• heat

• temperature

• phase

A blacksmith strikes a piece of metal with a hammer repeatedly. The metal slowly begins to glow as the temperature increases, and the metal becomes more malleable. Which changes on a microscopic level led to the visible changes in the properties of the metal? 

• The kinetic energy of the particles decreased.

• The individual temperature of the particles increased.

• The average speed of the particles increased.

• The potential energy of the particles decreased. 

Which statement best describes heat?

• Heat flows from hot to cold and is the transfer of thermal energy.

• Heat flows from cold to hot and is a form of thermal energy.

• Heat flows from cold to hot and is the transfer of thermal energy.

• Heat flows from hot to cold and is a form of thermal energy.

Thermal energy is added to ice and it begins to melt while remaining at the same temperature. Which changes happen to the molecules of water? 

• The molecules will have more potential energy because of their freedom to move

• The molecules will have a less average kinetic energy because of their movement.

• The molecules will have less potential energy because of their freedom to move.

• The molecules will have a greater average kinetic energy because of their freedom to move.

Use the table to answer the question.

A student places a drop of food coloring into two water samples. Her observations are shown in the table. Which statement best explains the observations in the table?

• The water molecules of sample 1 are transferring more kinetic energy.

• The temperature of sample 2 is close to freezing. 

• The temperature of sample 2 is higher. 

• The water molecules of sample 1 are moving faster.

Which experimental setup would let a student investigate the connection between kinetic energy and temperature?

• placing one drop of food coloring in a cup with 50 mL of water at 10ºC; placing two drops of food coloring in a second cup with 100 mL of water at 40ºC

• placing one drop of food coloring in a cup with 50 mL of water at 10ºC; placing one drop of food coloring in a second cup with 50 mL of water at 40ºC

• placing one drop of food coloring in a cup with 50 mL of water at 10ºC; placing one drop of food coloring in a second cup with 100 mL of water at 10ºC

• placing one drop of food coloring in a cup with 50 mL of water at 10ºC; placing two drops of food coloring in a second cup with 50 mL of water at 10ºC