Unit 1

 Energy cannot be created or destroyed  Energy can be transferred  “Cooling” is the transfer of heat energy from an object to its surroundings  If an object is cooling down, its surroundings will heat up until they both reach the same temperature  The transfer of heat energy is called enthalpy (∆H)

 Every reaction requires an input of energy to break the bonds in the reactants (left of the arrow)  When new bonds are created and products are formed (right of the arrow), energy is released

 If more energy is required to break the bonds in the reactant side than is released in the product side, the reaction is endothermic  If more energy is released when new bonds are formed than is required to break the original bonds, the reaction is exothermic

 Specific heat capacity is a constant value for every substance and can be used to identify a substance  It is the amount of energy required to raise the temperature of 1 gram of that substance by 1 ˚C  Unit for specific heat capacity is J/g ˚C  The formula for specific heat capacity is q=mC∆T  Q is the quantity of heat  M is mass  C is specific heat capacity  ∆T is change in temperature

 Water has a very high specific heat capacity compared to most other substances  This means it takes more energy to raise the temperature of water than it does to change the temperature of most other things