6 September Science 8 Recap temperature vs time graphs; phase changes in water; atoms and molecules; elements and compounds;

Opening routine.

1. Close devices, books, conversations, and eyes for a mindful moment. Breathe. Become calm. Focus. Consider the idea that Water is your real teacher. What is water saying in this photo? What does water teach about water? What does water teach about matter? What does water teach about “doing” science?
2. Review DSN entry from previous class.
3. Browse blogpost for today.
4. Prepare new document for DSN entry for today.
5. Questions. Share questions, periodic table apps, water property videos.
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Share/present and discuss graphs in large group.

Discuss the changes in the water you observed and where they occurred on the temperature curve. Include the points of discussion in your entry for today. Give credit for each partner’s comments and questions.

What are some possible interpretations of the part of the temperature curve where the water stopped cooling and the temperature remained constant for a while before it started cooling again? (One student thought the thermometer was broken during this phase of the cooling and freezing.)

What significance is there, do you think, in the temperature plateaus (flat sections) when water is heated and when it is cooled?

Consider these claims. Do your results support them? When water is liquid, the temperature of a sample can change. When water is solid, the temperature of a sample can change. When water changes from liquid to gas, the temperature of the sample does not change. When water changes from liquid to solid the temperature of the sample does not change. We have not tried to see if water in the gas form can change temperature, but what do you think? Could water vapor change temperature? What other observations with temperature did you make during either the heating or cooling of water?

What do the temperature vs time graphs of heating water and cooling water suggest about the relationship between matter and energy?

Check your evaporation experiments. Enter the data. I saw some discrepancies in some of the data entries. Please check. Is your name and your group’s data entered correctly on the spreadsheets? This may be a powerschool point.

What is the predominant pattern? What is the rate of evaporation– mass / unit of area / time as in: grams/square meter/hour ?

Fresh water evaporation:

Salt water evaporation:

Which has the greater rate of evaporation–the fresh water or the salt water?

To what extent does the rate of evaporation change over time for either batch?

How can the data be explained?

What are your ideas about evaporation? How do you think it occurs during boiling? How do you think it occurs at room temperature?

Do you think evaporation occurs at night? Why or why not?

What does evaporation “teach” us about matter and energy?

Periodic table:

Examine this creative periodic table: http://vis.sciencemag.org/chemhaiku/

And this one: http://elements.wlonk.com/

And this one: https://mymodernmet.com/illustrated-periodic-table/

With your partner, make a list of questions from your examination of the periodic table in different forms?

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The idea of atoms

Some properties and behaviors–The Periodic Table is organized by properties and behaviors of the elements

How exactly did Mendeleev discover his periodic table of 1869?

How small is an atom?

https://www.ted.com/talks/just_how_small_is_an_atom

Powers of ten?

Review:

How would you define in your own words, what an element is?

What elements do you know?

What elements have you held or touched in their pure form?

What do you think the relation is between element and compound? between atom and molecule? between pure substance and mixture?

With your partner, explore the following website. Identify your questions. What ideas are being proposed? Look at the sections on matter, atoms, elements, and the periodic table. Do not venture into chemical reactions. We will investigate those ideas later.

http://www.chem4kids.com/files/matter_intro.html

Define and distinguish–atom, molecule, element, compound, pure substance, mixture

Mass, volume, density

Properties (of water, for example)

Atoms from the Ring of Truth. Take notes and questions.

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Summative project will be introduced on Monday.