Phases of Matter
Phase with definite shape and definite volume
Solid
Solid → liquid
Melting
Term meaning “energy absorbed (energy in)"
Endothermic
A heating curve graphs temperature vs __________
Heat added
Intermolecular forces act __________ molecules
Between
Phase with definite volume but no definite shape
Liquid
Liquid → gas
Vaporization / Boiling (Evaporation acceptable)
Term meaning “energy released (energy out)”
Exothermic
Sloped sections show this is happening
Heating in one phase (temperature increasing)
Intramolecular forces act __________ molecules
Within
Phase with no definite shape or volume; particles far apart and moving rapidly
Gas
Gas → liquid
Condensation
Classify melting as endothermic or exothermic
Endothermic
Flat sections (plateaus) show this is happening
Phase change
Which is stronger overall: intermolecular or intramolecular?
Intramolecular
As kinetic energy increases, matter typically changes in this order
Solid → Liquid → Gas
Solid → gas
Sublimation
Classify condensation as endothermic or exothermic
Exothermic
During a plateau, energy goes into breaking these forces
Intermolecular forces
Order these from strongest to weakest: London dispersion, dipole–dipole, hydrogen bonding
Hydrogen bonding → Dipole–dipole → London dispersion
In this phase, particles are tightly packed and vibrate in fixed positions
Solid
Gas → solid
Deposition
During phase changes, temperature stays constant because energy is used to do this
Break or form intermolecular forces / separate or bring particles together
Name all five sections of the heating curve in order
Solid heating → Melting plateau → Liquid heating → Boiling plateau → Gas heating
Hydrogen bonding occurs when H is bonded to which 3 elements?
N, O, F