Evaporation and Condensation

1
Evaporation and Condensation

• Disappearing/Reappearing Trick

2
Questions to Ponder

• Have you ever had a cold drink on a hot day and
  after the glass sat for a while, the outside of
  the cup was all wet?
• Where did all that moisture come from?

3
Three States of Water

• Solid (Ice)
• Liquid (water)
• Gas (water vapor)

Red add heat
Blue remove heat
4
Evaporation

• Evaporation liquid changes to gas (vapor)

Note Water vapor is clear. Steam is not water
vapor.
5
Condensation

• Condensation gas changing to liquid

6
Putting It Together

• Why does a cold drink sweat?
• How does fog show up on a bathroom mirror?
• Why does dew appear on the leaves?
• Why does frost form?
• Why does a persons glasses fog up?
• Where does the foggy breath come from when a
  person exhales on a cold day?

7
Answer Condensation!

• Water vapor needs a colder temperature to change
  back to liquid, and a cold surface like a soda
  glass is perfect.
• When the air is moist (humid), condensation on
  cooler surfaces is likely to occur.