bond enthalpy
energy needed to break a bond in 1 mole of a gaseous substance
Born-Haber cycle
method to calculate the enthalpy of formation of a lattice structure
enthalpy (H)
internal energy of a system plus the work needed to displace the environment to produce the components of the system
Hess's law
law that states that in a multistep reaction, the reaction enthalpy is equal to the sum of the reaction enthalpies for each individual step
internal energy (U)
sum of all kinetic energy and potential energy of the particles in a system
lattice energy
energy needed to form a lattice structure (which always has a negative value)
standard state
set of specific conditions under which reactions are measured, typically 0°C and 1 atm pressure
system
part of the universe that is under consideration
work (w)
energy that is transferred when a force acts on an object over a distance