Do now
1 / 20

Do Now: - PowerPoint PPT Presentation

  • Uploaded on

Do Now:. Silently, independently you 10 minutes If you finish early you may read silently and independently Have your homework out on the top right corner of your desk. Today’s Topic: PHASE CHANGES!. Let’s Review…. Class Updates!.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Do Now:' - alea-rowland

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Do now
Do Now:

  • Silently, independently you 10 minutes

  • If you finish early you may read silently and independently

  • Have your homework out on the top right corner of your desk.

  • Today’s Topic: PHASE CHANGES!

Class updates
Class Updates!

  • Those that need to take the test/quiz need to do it by the end of this week! NO EXCUSES!

  • Don’t forget about participation tickets!

  • Extra credit will be given for boxes of tissue

  • I also have binders (only 8 for sale) for those of you still do not have a binder for my class!


  • Describe each of the six phase changes.

  • Identify phase changes as endothermic or exothermic.

  • By the end of the day you will be able to answer the following question: why does steam collect on the mirrors during a shower/bath?

Let s what some heat transfer and phase changes
Let’s what some heat transfer and phase changes

  • Predict what you think will happen

  • Write your observations in your notes

  • Tea bag

  • Why?

  • Think-Pair-Share

Phase change
Phase Change!

  • Is a reversible physical change that occurs when a substance changes from one state of matter to another.

  • Melting

  • Freezing

  • Vaporization

  • Condensation

  • Sublimation

  • Deposition

Temperature phase changes
Temperature & Phase Changes

  • Temperature of a substance DOES NOT change during a phase change.

Energy transfer
Energy Transfer

  • Energy is either absorbed or released during a phase change.

  • Endothermic: the system absorbs energy from the surroundings.

    • Example: ice melting.

  • Exothermic: the system releases energy to it’s surroundings

  • Example:?

How are we doing
How are we doing?

  • Name a phase change.

  • What happens to temperature?

  • What are the two types of energy of transfer?

Melting freezing
Melting & Freezing

  • The arrangement of molecules in water becomes less orderly as water melts and more orderly as water freezes

  • Melting: increase in average kinetic energy because energy (as heat) is added to the system and they begin to vibrate more quickly, until melting happens.

    • Example: ice-cream melting

  • Freezing: decrease in average kinetic energy because energy (as heat) leaves the system, thus molecules begin to slow until an orderly arrangement (frozen).

    • Example: an ice cube!

Vaporization condensation
Vaporization & Condensation

  • Vaporization: when changes from a liquid to a gas

    • Endothermic process, meaning?

    • Example: The refrigerators use evaporators to keep food cold

  • Evaporation is the process that changes a substance from a liquid to a gas at temperatures below the substance’s boiling point.

    • Example: puddles of rain disappear a few hours after a storm.

  • Boiling: takes place throughout a liquid, both the temperature and the vapor pressure of the water increases.

    • Kinetic energy increases!

  • What vapor pressure?

    • The pressure caused by the collisions of vapor particles on a container!

Vaporization condensation continued
Vaporization & Condensation Continued

  • Condensation: is the phase change in which a substance changes from a gas or vapor to a liquid.

    • Example: the steam on your bathroom mirror.

      • This is because water vapor cooled as it came in contact with the mirror. The water vapor transferred heat to the mirror and CONDENSED into a liquid.

  • It is an exothermic process.

  • Sublimation deposition
    Sublimation & Deposition

    • Sublimation: is the phase change in which a substance changes from a solid to a gas or vapor without changing to a liquid at first.

    • This is an endothermic process

      • Examples: as dry ice melts, it sublimes because the cold carbon dioxide vapor causes the water vapor in the air to condense and form clouds

    Sublimation deposition continued
    Sublimation & Deposition Continued…

    • Deposition: when a gas or a vapor changes directly into a solid without first changing into a liquid.

    • This is an exothermic process (reverse of sublimation).

    • Examples: frost forming on windows, because when water vapor contacts windows it looses enough energy to change from a gas to a solid.

    Essential question answered
    Essential Question Answered

    • So… why is there a ‘cloud’ on the mirror in the bathroom after a shower?

      • 1. The water molecule on the surface of the bath water evaporates (endothermic).

      • 2. Random motion carries it the surface of the mirror.

      • 3. The water molecule condenses on the mirror (exothermic).

    Exit ticket summarize today s notes
    Exit Ticket = Summarize Today’s Notes

    • Take the change to review your notes from today.

    • Draw a line and under the line begin a summary.

    • Use your own words!

    • Use pictures!