Question

which of these statements are consistent with kinetic-molecular theory? choose three correct answers.

• the particles of matter in the sun are in constant random motion.
• if you superheat a gas, its particles eventually stop moving completely.
• the molecules in water at \\(100^\circ\text{c}\\) have more kinetic energy than the molecules in water at \\(0^\circ\text{c}\\).
• the carbon atoms in a diamond vibrate back and forth in place.
• as a solid is heated, its particles absorb thermal energy and move more slowly.

Explanation:

Analyze Kinetic-Molecular Theory principles

The Kinetic Molecular Theory states that all matter is made of particles that are in constant, random motion. The average kinetic energy of these particles is directly proportional to the absolute temperature of the substance.

Evaluate each statement

• Statement 1: "The particles of matter in the sun are in constant random motion."

This is consistent with the theory, as particles in all states of matter (including plasma in the sun) are in constant random motion.

• Statement 2: "If you superheat a gas, its particles eventually stop moving completely."

This is incorrect. Heating a gas increases particle speed; particles only theoretically stop moving at absolute zero (\(0\text{ K}\)).

• Statement 3: "The molecules in water at \(100^\circ\text{ C}\) have more kinetic energy than the molecules in water at \(0^\circ\text{ C}\)."

This is correct because temperature is a direct measure of average kinetic energy.

• Statement 4: "The carbon atoms in a diamond vibrate back and forth in place."

This is correct. In solids, particles are held in fixed positions but still vibrate back and forth.

• Statement 5: "As a solid is heated, its particles absorb thermal energy and move more slowly."

This is incorrect. Absorbing thermal energy increases kinetic energy, causing particles to move faster.

Select the three correct statements

The three statements consistent with the theory are Statement 1, Statement 3, and Statement 4.

Answer:

• The particles of matter in the sun are in constant random motion. (Correct answer)
• If you superheat a gas, its particles eventually stop moving completely.
• The molecules in water at \(100^\circ\text{ C}\) have more kinetic energy than the molecules in water at \(0^\circ\text{ C}\). (Correct answer)
• The carbon atoms in a diamond vibrate back and forth in place. (Correct answer)
• As a solid is heated, its particles absorb thermal energy and move more slowly.