14.3 Internal Energy Flashcards
Define internal energy
The sum of the randomly distributed kinetic and potential energies of atoms or molecules within a substance
Does frozen water have 0 internal energy
No, the kinetic energy is 0 however the molecules still have electrostatic potential energy stored between the particles
At 0 K is the potential energies of the molecules 0
No you cannot reduce the potential energy of the substance to 0 even at 0k
When changing state does a substances internal energy change
Yes, the kinetic energy nor temperature doesn’t change yet the internal energy does significantly
State the potential energies within gases
0, negligible forces between atoms/molecules
State the potential energies within liquids
Electrostatic forces give the electrostatic potential energies a negative value meaning that energy needs to be supplied to break the atomic/molecular bonds
State the potential energies within solids
Electrostatic forces between atoms/molecules are large so electrostatic potential energy has large negative value = lots of energy required to break
