# Ib Physics Chapter 3 Notes

Topics: Thermodynamics, Temperature, Energy Pages: 3 (971 words) Published: November 25, 2012
I did not understand how to explain why temperature does not change during a phase change and am not entirely sure if I have accurately or thoroughly described 3.2.3 and 3.2.4. This is also the case for 3.2.12

Thermal Physics

Thermal Concepts:

Temperature (T) is a measure of how hot or cold an object is, and it is the temperature that determines the determines the direction of thermal energy transfer between two objects. It is a scalar quantity and is measure in degrees celcius (°C ) or kelvin (K). 0 °C is equal to -273K. Kelvin is based on the properties of a gas. Thermal energy is the receiving of energy from a hot body by a cold body when placed next to each other. Internal energy of a substance is the total potential energy and random kinetic energy of the molecules of the substance. It is where molecules in a body gain energy internally and are able to be move faster (increased KE) and move apart (increased PE) from work being acted upon it. Moles:

• A mole of any material contains 6.022×10^23 atoms or molecules. This is also known as Avogadro's constant. • However, all moles don't have the same mass due to the different types of particles which have different mass

Thermal Properties of Matter:

Specific Heat Capacity (C) of a material is the amount of heat required to raise the temperature of 1kg of the material by 1°C. It is measured in J × °C / kg. It is expressed by the equation: c = Q/ mΔT; where m is mass, Q is the quantity of heat and ΔT is the change in temperature. Thermal Capacity (c) of a material is the amount of heat needed to raise the temperature by 1°C. It is measured in J / °C . It is expressed by the equation: C = Q/ ΔT; where Q is the quantity of heat added and ΔT is the amount of increase in temperature of a body. The physical difference between liquids, solids and gaseous phases in terms of molecular structure and particle motion involve atoms having KE and having strong attraction...