Flashcards in Topic 3.2: Thermal Properties of Matter Deck (16)
Define specific heat capacity
o SPECIFIC HEAT CAPACITY: The amount of thermal energy required to raise the temperature of 1kg of a substance by 1K
Define thermal capacity
o THERMAL CAPACITY: The amount of thermal energy required to raise the temperature of an object by 1K.
Define microscopic description
o MICROSCOPIC DESCRIPTION: Considers properties of matter at a particle level. Molecules are in motion and collide with each other and the container.
Define kinetic energy of particles
o KINETIC ENERGY OF PARTICLES: Temperature is a measure of the average kinetic energy of the particles.
• 3.2.3: Explain the physical difference between the solid, liquid, and gaseous phases in terms of molecular structure and particle motion
o PHASES OF MATTER: Particles in a solid are locked into the crystal structure and do not have enough KE to escape. In a liquid, they overcome the chemical bonds but cannot separate completely for the other atoms. The particles in a gas have enough KE to escape from each other.
o Solids –fixed positions, many strong bonds (potential energy)
o Liquids – Changing positions, many temporary bonds
o Gases – Free moving, no bonds
What is the process of going from a gas to a solid?
What is the process of going from a solid to a gas?
What is the process of going from a solid to a liquid?
What is the process of going from a liquid to a solid?
What is the process of going from a liquid to a gas?
What is the process of going from a gas to a liquid?
• 3.2.6: Distinguish between evaporation and boiling
o EVAPORATION: The process by which faster-moving molecules escape from the surface of a liquid. This results in a cooling of the liquid.
o BOILING: The process by which a liquid changes into a solid at the constant temperature of the boiling point.
• 3.2.9: Define pressure and microscopic description of pressure
o PRESSURE: The force exerted per unit area. Measured in pascals.
o MICROSCOPIC DESCRIPTION OF PRESSURE: Many moving particles exert forces when they collide with container walls give the effect of pressure being exerted by the gas.
Define ideal gas
o IDEAL GAS: A theoretical gas composed of a randomly moving non-interacting particles. It is a useful idea because many real gases behave like an ideal gas unless temperature or pressure are very high or low.
• 3.2.10: State the assumptions of the kinetic model of an ideal gas (6)
o KINETIC MODEL OF AN IDEAL GAS: A model which treats a gas as many molecules subject to the following assumptions:
The molecules obey Newton’s laws
The intermolecular forces are negligible
The molecules are spherical with negligible volume
The motion of the molecules is random.
The collisions are perfectly elastic.
The time taken for a collision is negligible.