Heat part 1

• Energy

  Something that has the ability to do work. Ex: it can move something, change the state of something, etc
• Kinetic molecular theory

  Theory that all matter is made up of particles that are constantly in motion
• Important postulates of kinetic molecular theory

  All matter consists of atoms, atoms may join together to form molecules, molecular motion in random, molecules in motion possess kinetic energy, molecular motion is greatest in gases, less in liquids, and least in solids, collisions between atoms and molecules transfer energy between them
• Thermal energy

  The total energy (kinetic and potential) possessed by particles moving in object.
• Heat (Q)


  Thermal energy transferred from one object to another. Transfer is caused by difference in temperature between objects. Can only be transferred from a hotter body to cooler body. Measured in Joules (J).
• Three ways thermal energy can be transferred

  Conduction, convection, radiation
• Conduction


  Energy is passed by particles bumping into each other. Fast moving particles bump into slowly moving particles, transferring energy, making them move faster.
• Convection

  When given substance is heated, particles rise because substance is less dense. Rising particles create a currant which cause cooler particles to circulate down. The cooler particles then heat up and rise, starting the cycle over again.
• Radiation

  Transfer of energy through electromagnetic waves, not matter
• Temperature


  The "hotness" of an object measured on a specific scale (°C, °F, K). Average energy of particles in a substance.
• Thermal equilibrium

  Two objects become the same temperature
• Celsius scale


  Temperature scale calibrated to the physical properties of water
• Kelvin scale

  Temperature scale based on energy.
• Formula for converting Celsius to kelvin

  K=C+273
• Thermal expansion

  The expansion of an object as it heats up
• Linear expansion

  The length of an object increasing as it heats up
• Formula for linear expansion


  ΔL=aLΔT
• Volumetric expansion

  Volume of an object expanding as temperature increases
• Formula for volumetric expansion


  ΔV=BVoΔT
• Specific heat capacity (c)

  Quantity of heat required to raise the temperature of 1kg of a substance by one degree Celsius or kelvin
• Formula for determining how much heat is absorbed or released during a temperature change

  Q=mcΔT
• Heat exchange of mixtures formula

  Q1=-Q2
• Latent heat (kJ/kg)


  Quantity of heat needed to change the state of 1kg of a certain substance
• Latent heat of fusion

  Amount of energy released or absorbed to solidify or melt a substance
• Latent heat of fusion equation

  Qf=mHf
• Latent heat of vaporization

  Amount of heat energy released or absorbed to condense or vaporize a substance
• Equation for latent heat of vaporization

  Qv=mHv
• When energy is released latent heat is..

  Negative