Chapter 3, Section 3 Flashcards
change of state
the change of a substance from one physical form to another(or phase changes). All changes of state are physical changes.
what changes a substance from one state to another?
you must add or remove energy.
endothermic change
energy is gained by the substance(heat goes in)
exothermic change
energy is removed from the substance(heat exits)
melting
the change of state from solid to liquid;
endothermic change
melting point
the temperature at which a substance changes from solid to liquid
do different substances have different melting points?
yes. for example, galliums is 30°C and salts is 801°
freeing
the change of a state from liquid to solid; exothermic change
what happens as the temperature decreases?
the particles move slower
freezing and melting points are the same temperature. true or false?
true
vaporization
the change of a liquid to a gas
evaporation
the change of a state from liquid to gas at the surface of a liquid; energy is added from surroundings(endothermic change)
boiling
the change of a liquid to a vapor throughout the liquid
boiling point
the temperature at which a liquid boils
when does the boiling point change?
when the atmospheric pressure changes
