MELTING-ICE VIDEO: TEACHER PAUSE PLAN

Match the pauses and observations to the video you choose.

EXAMPLE SETTING
Ice on a dish at ordinary room temperature, above 0 degrees Celsius.
Use a clip that identifies this setting, keeps the dish clearly in view and
shows no water being poured into it. A time-lapse clip speeds up the change;
playback time is not a measurement of melting time.

PAUSE A - BEFORE THE CHANGE
Stop before the result appears.

Student prompt:
What do you predict will happen to ice on a dish at ordinary room temperature?
Give one reason for your prediction.

Teacher notes:
Record this as a prediction, not a correct-answer checkpoint.
Have students keep a copy on paper to reread at the last stop.
"I think it will melt because the room is warmer" is reasonable.
"I think it will stay solid because there is no heater" is an idea to revisit.

Optional teacher narration:
Keep your prediction. Now watch for changes in the ice and anything that
collects around it.

WATCH THE MELTING SEQUENCE WITHOUT ANOTHER QUESTION HALFWAY THROUGH

PAUSE B - AFTER A VISIBLE CHANGE, BEFORE THE EXPLANATION
Some ice may still remain. Stop before narration explains why it happened.

Student prompt:
Describe two changes you can see. Begin with "At first..." and "Later...".
Keep reasons out of this answer.

Answer guide for the illustrated storyboard:
At first, there was a large piece of ice on the dish. Later, the ice was
smaller and liquid had collected around it.

Accept accurate observations of the actual clip, even when they differ from
the storyboard. Do not accept "all the ice melted" if ice is still visible.
For an explanation such as "It melted because it got warmer", ask:
What on the screen helped you decide that?
The video alone supplies no thermometer reading.

LET THE WHOLE EXPLANATION FINISH

If the chosen clip has no explanation, say this narration aloud or
put it on a note slide after the video:

Ice is water in its solid state. Melting changes solid water into liquid
water. In this room-temperature setting, energy transfers from the warmer
surroundings to the ice and helps it melt. The water has changed state;
it has not become a new substance.

PAUSE C - AFTER THE EXPLANATION

Student prompt:
Explain the change in two sentences.
"I saw _____. This is melting: _____ changed from _____ to _____."
Then compare it with your prediction.

Answer guide:
The first sentence names visible evidence. The last three blanks are:
water / solid / liquid.

Example for the storyboard:
I saw smaller ice and liquid collecting around it. This is melting:
water changed from solid to liquid.

Students may add energy from warmer surroundings. They should not invent an
exact temperature or melting time. For "The ice disappeared", follow up with:
Where is the water now?

Return to the prediction on paper. Ask students to name the observation that
supported their prediction or changed their mind.

SCIENCE REFERENCE
American Chemical Society, Lesson 2.5: Changing State - Melting
https://www.acs.org/middleschoolchemistry/lessonplans/chapter2/lesson5.html

DECK.TOYS SETUP REFERENCE
How to Use the Interactive Video Feature in Deck.Toys (January 2, 2022)
https://blog.deck.toys/how-to-use-interactive-video/