Question 1: Define melting and describe the process in terms of particle movement.

Answer: Melting is the change of a solid into a liquid when particles gain enough energy to overcome their fixed positions, increasing their movement.

Question 2: What is vaporization, and how does it differ from boiling?

Answer: Vaporization is the process of a liquid changing into a gas. Boiling is a type of vaporization that occurs throughout the liquid at its boiling point.

Question 3: Explain sublimation with an example.

Answer: Sublimation is the direct change of a solid into a gas without passing through the liquid state, such as dry ice (solid carbon dioxide) turning into gas.

Question 4: Describe the process of condensation and its significance in the water cycle.

Answer: Condensation is the change of a gas into a liquid when particles lose energy and come closer together, forming droplets. It is essential in the water cycle as it forms clouds and rain.

Question 5: Which state change involves particles moving from a gas directly to a solid? Name the process and give an example.

Answer: Deposition involves particles moving directly from a gas to a solid, such as frost forming from water vapor.

Question 6: A piece of ice at -10°C is heated until it melts. Describe the energy changes involved during melting.

Answer: During melting, heat energy is supplied to the ice, increasing the particles' kinetic energy until they overcome their fixed positions. The temperature remains constant at 0°C during the phase change until all ice turns into water.

Question 7: Calculate the amount of heat required to melt 50 grams of ice at 0°C. (Specific heat of fusion of ice = 334 J/g).

Answer: Q = mass × specific heat of fusion = 50 g × 334 J/g = 16,700 Joules

Question 8: Identify the phase change described: 'Water vapor turns into droplets on a cold mirror.'

Answer: Condensation

Question 9: Fill in the blank: When a liquid is heated to its boiling point, the process of __________ occurs throughout the liquid.

Answer: vaporization

Question 10: Explain how understanding state changes is important in industrial applications, providing one example.

Answer: Understanding state changes is crucial in industries like food preservation, where freezing and thawing control spoilage, or in refrigeration systems that rely on vaporization and condensation cycles to transfer heat efficiently.