Lecture 5.2: Matter Changing States

8th Grade Physical Science Ms. McKinley

! Intro ! We already know the 4 states of matter:!! SOLID!! LIQUID!! GAS!! PLASMA

! QUESTION:!! Is it possible for matter to

change from one state to another??

! Intro ! We already know the 4 states/phases of matter:!! SOLID!! LIQUID!! GAS!! PLASMA!!

! YES, a substance can change phase.!! This is done by adding or removing

THERMAL ENERGY!!

! THERMAL ENERGY = heat.

! Thermal Energy

! When THERMAL ENERGY is added to a substance, the temperature increases (goes up).!

! The particles start to move faster.!!!

! When THERMAL ENERGY is removed, the temperature decreases (goes down).!

! The particles start to move slower

! Changes b/t SOLIDS and LIQUIDS

! MELTING!! SOLID ! LIQUID!! Happens when the temperature is increased

to the melting point (melting temperature).!!!

! FREEZING!! LIQUID ! SOLID!! Happens when the temp. is decreased to the

freezing point (freezing temperature).!!

! FREEZING and MELTING are OPPOSITES

! Changes b/t LIQUIDS and GASES

! VAPORIZATION!! LIQUID ! GAS!! Happens when the temp. of a liquid is

increased. Can happen in 2 ways:!! EVAPORATION: vaporization @ a liquid’s

surface!! BOILING: vaporization inside a liquid!

!! CONDENSATION!

! GAS ! LIQUID!! Happens when the temp. of a gas is

decreased.!!

VAPORIZATION and CONDENSATION are opposites

! Changes b/t SOLIDS and GASES

! SUBLIMATION!! SOLID ! GAS!!

! DEPOSITION!! GAS ! SOLID!

SUBLIMATION and DEPOSITION are opposites.

! Physical Processes

! Freezing, Melting, Boiling, Sublimation, etc. are all examples of PHYSICAL PROCESSES.!!

! When these processes happen, the substance still keeps its identity.!!

! WATER is still WATER whether it’s liquid, solid, or gas. It’s still H2O!

Whoa, what does THAT

mean?

These are ALL water!