Question 1: Define the Particle Model of matter in your own words.

Answer: The Particle Model describes matter as made up of tiny particles that are in constant motion, with the arrangement and energy of these particles determining the state of the substance.

Question 1: Explain how particle movement differs between solids, liquids, and gases.

Answer: In solids, particles are tightly packed and only vibrate in fixed positions. In liquids, particles are less tightly packed and can move past each other. In gases, particles are far apart and move freely at high speeds.

Question 1: A sample of water is heated from 0°C to 100°C. Describe what happens to the particles during this process and how it relates to the data.

Answer: As water is heated from 0°C to 100°C, the particles gain kinetic energy, moving faster. During the boiling point, the particles have enough energy to overcome intermolecular forces, leading to a phase change from liquid to gas. The data shows an increase in temperature until boiling, where temperature remains constant during the phase change.

Question 1: Calculate the amount of energy required to raise the temperature of 2 grams of sulphur from 25°C to 100°C. The specific heat capacity of sulphur is 0.71 J/g°C.

Answer: Energy = mass × specific heat capacity × temperature change = 2 g × 0.71 J/g°C × (100°C - 25°C) = 2 × 0.71 × 75 = 106.5 Joules.

Question 1: Describe a simple experiment to demonstrate the effect of temperature on particle movement in a gas, including variables and safety precautions.

Answer: A practical experiment could involve heating a sealed container of air and observing the expansion or measuring pressure changes at different temperatures. The independent variable is temperature, the dependent variable is pressure or volume, and safety precautions include using heat-resistant gloves and eye protection to handle hot equipment safely.

Question 1: Explain how understanding the Particle Model is important in the design of refrigeration systems.

Answer: Understanding the Particle Model helps in controlling particle movement and energy transfer, which is essential for efficient cooling. It allows engineers to design systems that manipulate particle energy and phase changes to remove heat effectively.

Question 1: Describe how the Particle Model aids in understanding the operation of a modern heat pump.

Answer: The Particle Model explains how refrigerant particles absorb and release energy during phase changes, enabling the heat pump to transfer heat from cooler to warmer areas efficiently. Particle behaviour during compression and expansion cycles is fundamental to its operation.