Download Changes of State

CHANGES OF STATE
Chemistry Standard 7c
WHAT IS A CHEMICAL CHANGE?
Two or more substances react and make
something completely different
 Example:

Something burns
 rusting
 Explosive sodium and poisonous chlorine make table
salt (Na + Cl  NaCl)

WHY IS SALT SO STABLE?
When salt is made, it forms a lattice, or a strong
cube structure.
 Positive Sodium is attracted to negative Chlorine

WHAT IS A PHYSICAL CHANGE?
Change in size, shape, amount, state but NOT a
change in substance!
 Examples:






ice melting
Cutting an apple in half
Pouring Mt. Dew into a glass
Melting point
Boiling point
Description of
Phase Change
Term for Phase
Change
Heat Movement
During Phase
Change
Solid to liquid
Melting
Heat goes into the
solid as it melts.
Liquid to solid
Freezing
Heat leaves the
liquid as it freezes.
Liquid to gas
Vaporization, which
includes boiling and
evaporation
Heat goes into the
liquid as it vaporizes.
Gas to liquid
Condensation
Heat leaves the gas
as it condenses.
Sublimation
Heat goes into the
solid as it
sublimates.
Solid to gas
IMPORTANT VOCABULARY
Boiling point: temperature at which a liquid
turns into a gas (Endothermic)
 Freezing Point: temperature at which a liquid
turns into a solid (exothermic)
 Melting Point: temperature at which a solid
turns into a liquid (endothermic)
 Condensation: process of gas becoming liquid
 Vaporization: process of liquid becoming gas
 Sublimation: process of a solid turning into a gas


Watch water go
through phase changes!
Here