Question 1 (1 point)

Question

A mixture of gases is heated and rises to the top of its container. Which statement best explains this result?

a
Heated gases will have decreased kinetic energy and increased density.
b
Heated gases will have increased kinetic energy and increased density.
c
Heated gases will have increased kinetic energy and decreased density.
d
Heated gases will have decreased kinetic energy and decreased density.
Question 2 (1 point)
An aluminum block with a temperature of 300 oC is placed into 200 milliliters of water with a temperature of 20 oC. Which statement best describes what will be observed in this experiment?

a
Heat will flow from the metal to the water until both are at the temperature of the container.
b
Heat will flow from the metal to the water until both are at a temperature somewhere between 20oC and 300oC.
c
Heat will flow from the metal to the water until both are 20 oC.
d
Heat will flow from the metal to the water until both are 300 oC.

Answer 1

Question 1: The correct answer is c. Heated gases will have increased kinetic energy and decreased density. As gases are heated, their molecules gain kinetic energy, causing them to move faster and spread out, resulting in decreased density. This lower density allows the heated gas to rise.

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Question 2: The correct answer is b. Heat will flow from the metal to the water until both are at a temperature somewhere between 20°C and 300°C. Heat transfer occurs from the hotter object (aluminum block) to the cooler one (water) until thermal equilibrium is reached, which will be a temperature that is between the two initial temperatures.