The laws of thermodynamics describe the essential role of energy and explain/predict the direction of changes in matter.
Section 1: Heat
"Heat'em up, speed'em up". Temperature of a system is direct meausre of kinetic energy in a system. The higher the temperature the more random motion is present. This is why 2 systems at different temperatures, when placed in contact with each other, will exchange thermal energy (Heat). The heat is transferred through molecular collisions from high kinetic energy to low kinetic energy.
Section 2: Law of Conservation of Energy
Energy cannot be created or destroyed. A change in energy of a system must be balanced by either a transfer of energy into or out of that system. The change in energy will be proportional to the amount of substance and is best described as per mole or per gram of that substance.
Section 3: Bond Energy
Breaking bonds requires energy and forming bonds releases energy!
Section 4: Not all changes in energy are breaking/forming bonds
Remember electrostatic forces also exist BETWEEN molecules in the form of inter-molecular interactions. It is important to be able to distinguish between energy associated with chemical changes and physical changes.
Section 5: Is the process favorable or unfavorable?
One of the main applications of thermodynamics is to answer the above question. Chemical and physical changes can be driven by an increase in entropy, a decrease in enthalpy, or both. Free energy (G) takes both factors into account to determine if a process will be thermodynamically favorable or thermodynamically unfavorable.