Question 1: Which of the following best describes the arrangement of particles in a solid?

Answer: Particles are closely packed in a fixed position.

Question 2: Match the following terms to their definitions:

Answer: See full answer key

Question 3: Fill in the blanks: The _______ model of matter explains that matter is made up of small, _______ particles.

Answer: particle, discrete

Question 4: True or False: The particles in a gas are in constant, random motion.

Answer: True

Question 5: True or False: Solid particles have the most energy compared to liquids and gases.

Answer: False

Question 6: Explain how the particle model of matter accounts for the differences in density between solids, liquids, and gases.

Answer: In solids, particles are tightly packed, leading to higher density. In liquids, particles are less tightly packed, leading to lower density. In gases, particles are widely spaced, resulting in the lowest density.

Question 7: Describe the process of melting using the particle model.

Answer: Melting occurs when particles in a solid gain energy and begin to move more freely, changing into the liquid state.

Question 8: What happens to the particles of a substance when it is heated?

Answer: The particles gain energy and move faster.

Question 9: Calculate the density of a substance with a mass of 200g and a volume of 50cm³. Use the formula: Density = Mass/Volume.

Answer: 4 g/cm³

Question 10: Order the following processes of matter in terms of increasing energy: Condensation, Freezing, Evaporation.

Answer: See full answer key

Question 11: Discuss the changes in particle energy and arrangement during the process of sublimation.

Answer: Sublimation is the transition of a substance from solid to gas without passing through the liquid state. During sublimation, particles absorb energy, which increases their movement and allows them to break free from their fixed positions in the solid. As the particles gain enough energy, they become widely spaced and move freely as gas particles.