Heated gases will rise to the top of its container. Why does this occur?(1 point)

Question

Responses

Heated gases will increase in kinetic energy and increase in density.
Heated gases will increase in kinetic energy and increase in density.

Heated gases will increase in kinetic energy and decrease in density.
Heated gases will increase in kinetic energy and decrease in density.

Heated gases will decrease in kinetic energy and decrease in density.
Heated gases will decrease in kinetic energy and decrease in density.

Heated gases will decrease in kinetic energy and increase in density.

Answer 1

Heated gases will increase in kinetic energy and decrease in density.

As the temperature of a gas increases, its molecules gain kinetic energy and move more rapidly. This increased movement causes the gas to expand, resulting in a lower density. Because warmer (less dense) gases are buoyant compared to cooler (denser) gases, the heated gases rise to the top of their container.

Answer 2

An ice cube is placed on a metal block that is at a room temperature of 30oC. Which statement describes the transfer of heat between the ice cube and metal block?(1 point)
Responses

Heat is transferred from the air to the ice cube, and the ice melts.
Heat is transferred from the air to the ice cube, and the ice melts.

Heat is transferred from the ice cube to the air, and the ice melts.
Heat is transferred from the ice cube to the air, and the ice melts.

Heat is transferred from the ice cube to the metal block, and the ice melts.
Heat is transferred from the ice cube to the metal block, and the ice melts.

Heat is transferred from the air and metal to the ice cube, and the ice melts.

Answer 3

The correct statement is:

Heat is transferred from the metal block to the ice cube, and the ice melts.

In this scenario, the metal block is at a higher temperature (30°C) compared to the ice cube (which is at or below 0°C). Heat will naturally flow from the hotter object (the metal block) to the cooler object (the ice cube), causing the ice to absorb heat and melt.

Answer 4

Lucy is making a cup of hot chocolate. She puts the chocolate and hot water into a cup, and stirs the mixture.

A few minutes later, she notices the cup and the spoon have gotten hot. What made Lucy’s cup and spoon get hot?

(1 point)
Responses

Heat was transferred through conduction to the cup and spoon when the hot water molecules collided frequently with the cooler molecules in the cup and spoon and transferred heat.
Heat was transferred through conduction to the cup and spoon when the hot water molecules collided frequently with the cooler molecules in the cup and spoon and transferred heat.

Heat was transferred through convection to the cup and spoon when the hot water molecules moved through the cooler molecules in the surrounding air and transferred heat.
Heat was transferred through convection to the cup and spoon when the hot water molecules moved through the cooler molecules in the surrounding air and transferred heat.

Heat was transferred through convection to the cup and spoon when the hot water molecules radiated into the cooler molecules of the hot chocolate mix and transferred heat.
Heat was transferred through convection to the cup and spoon when the hot water molecules radiated into the cooler molecules of the hot chocolate mix and transferred heat.

Heat was transferred through conduction to the cup and spoon when the hot water molecules flowed in currents through the cooler molecules of the hot chocolate mix and transferred heat.
Heat was transferred through conduction to the cup and spoon when the hot water molecules flowed in currents through the cooler molecules of the hot chocolate mix and transferred heat.

Answer 5

The correct response is:

Heat was transferred through conduction to the cup and spoon when the hot water molecules collided frequently with the cooler molecules in the cup and spoon and transferred heat.

Conduction is the process through which heat is transferred directly through collisions between molecules. In this case, the hot water warms the cup and spoon through direct contact, resulting in heat transfer.

Answer 6

The picture below shows two flasks, one with hot water and one with room temperature water, which are connected by a conductive metal bar.

In which direction does the thermal energy between the flasks flow?

(1 point)
Responses

Thermal energy flows equally between the two flasks.
Thermal energy flows equally between the two flasks.

Thermal energy does not flow between the two flasks.
Thermal energy does not flow between the two flasks.

Thermal energy flows from the flask with room temperature water to the flask with hot water.
Thermal energy flows from the flask with room temperature water to the flask with hot water.

Thermal energy flows from the flask with hot water to the flask with room temperature water.
Thermal energy flows from the flask with hot water to the flask with room temperature water.

Answer 7

The correct response is:

Thermal energy flows from the flask with hot water to the flask with room temperature water.

Thermal energy naturally flows from hotter objects to cooler objects until thermal equilibrium is reached. In this case, the thermal energy will flow from the hot water flask to the room temperature water flask through the conductive metal bar connecting them.

Answer 8

Which type of energy transfer can take place without matter present?(1 point)
Responses

Radiation
Radiation

Insulation
Insulation

Conduction
Conduction

Convection ​​​​​​​
Convection ​​​​​​​

Answer 9

The correct response is:

Radiation

Radiation is the transfer of energy in the form of electromagnetic waves, such as infrared radiation, and it can occur in a vacuum where no matter is present. In contrast, conduction and convection both require matter to transfer heat.