GEMS project

SOURCE OF THE LESSON: Matter- Solids, Liquids & Gases: GEMS© Teacher’s Guide for Grades 1-3 from Lawrence Hall of Science: Activity #3 (pgs 45-56); www.lhsgems.org

TEKS ADDRESSED:

Science 2.2(e)(f) 2.3(a) 2.5(a)

2.2 (e) Construct reasonable explanations and draw conclusions using information and prior knowledge

2.2 (f) Communicate explanations about investigations

2.3 (a) Make decisions using information

2.5 (a) Classify and sequence organisms, objects, and events based on properties and patterns

English Language Arts and Reading 2.14(a)

2.14 (a) Write to record ideas and reflections

CONCEPT STATEMENT: Solids hold their shape and do not make a puddle can be a powder and can be smashed. Liquids do not hold their shape, do make a puddle, take the shape of their container, stay flat on top unless moving and can splash. Granular substances are solids (such as sand and powder). Piles of tiny bits of solids are still solids even though they can be poured. Some substances do not fit neatly into categories such as toothpaste, and shaving cream. Investigative, thinking and discussion skills are used when exploring and deciding how to categorize challenging substances. (GEMS Guide: Matter)

PERFORMANCE OBJECTIVES: Students will be able to:

Reinforce their understanding of solids and liquids,
Understand that materials such as powder and sand are solids,
Apply definitions of solids and liquids,
Base their explanations on evidence,
Use simple tools to collect and measure substances and
Follow directions; work cooperatively in groups, and record data

RESOURCES:

For the class:

· Solids and Liquids display from previous session
· Rock and few other solid and liquid items from previous sessions
· Small amount of baking soda
· 1 clear plastic cup

For each student:

· Journal from previous sessions
· One copy of the Solid or Liquid? student sheet (pg 54)
· Pencils

For the toothpaste, shaving cream, and sand stations (two of each):

· 4 cafeteria trays
· 4 trash containers
· About a cup of shaving cream
· About ½ tube of toothpaste
· Toothpicks
· About a cup of sand
· 6 wide-mouth plastics cups
· 8 magnifying lenses OR handheld microscopes
· 4 dishtubs for washing hands
· Paper towels
· Water
· 2 dustpans and brooms for cleanup

For to Glook stations:

· A 1-teaspoon measuring spoon
· A 1-tablespoon measuring spoon
· 2 sealable plastic bags or other airtight containers
· 8 tablespoons of white glue
· 8 tablespoons of water
· 2 cups
· 1 stirrer
· 4 teaspoons of Borax powder
· 1 cup of warm water

SAFETY CONSIDERATIONS: Students will

· Walk from station to station
· Keep everything away from their mouths
· Try to keep sand and Glook off of the floor
· Use the broom and dustpan to clean up spills promptly and appropriately
· Only use the toothpicks to examine toothpaste then throw away when finished
· Wash hands

SUPLEMENTARY MATERIALS, HANDOUTS:

· Student journals
· Solid or Liquid? sheet (pg 54 of GEMS Guide)

Engagement: Review Solids and Liquids Introduce Challenging Substances		Time: 5 min Time: 5 min
What the Teacher Will Do	Probing Questions	Student Responses Potential Misconceptions
Introduce hand signals: Closed fist = solids Slowly waving hand = liquids
Hold up examples of solids and liquids	Is this a solid or a liquid? Why?	Show appropriate hand signal without verbalizing answer
Hold up a container with liquid in it	Is everything in my hand a solid or a liquid? Why?	Show appropriate hand signal(s) without verbalizing answer. Students may be confused since there is a solid and a liquid held up.
Draw attention to class display and review definitions of solids and liquids	How de we define a solid? How else? How do we define a liquid? How else?	Solids hold their shape, do not make a puddle, can be smashed, etc. Liquids don’t hold their shape, do make a puddle, can splash, etc.
Introduce challenging substances: shaving cream, toothpaste, Glook and sand. Let students know these may be hard to classify and they will be working together to do their best in deciding.	Are these items solids or liquids? Why do you think that? Could it also be (different response)? Why / why not?	Students give hand signals Items hold qualities of both definitions and can be confusing. Answers may include solid, liquid, both, neither, and I don’t know.

Exploration Introduce Procedure Conduct Learning Stations		Time: 5-10 min Time: 15-20 min
What the Teacher Will Do	Probing Questions	Student Responses Potential Misconceptions
Tell students they will be going to 4 total stations with a partner to try and figure out if each substance is a solid or liquid and record their decision on the worksheet.	How many stations are set up? How many will we visit? Do we go to a station that has a substance we have already classified?	[8 set up, 4 to visit] 8 set up, 8 to visit [Yes] No 8 stations will be set up, 2 for each substance Make sure students understand they will only need to visit 4 different stations each with a different substance.
Pass out Solid or Liquid? sheets to each student. Point out where students will record their data. Have them write their name up top.
Demonstrate steps for each station
Say that when it is time, take your Solid or Liquid? sheets and a pencil and walk to a station with your partner	How will we get to our stations?	We walk
Say that once there, use your senses to investigate the substance looking for evidence of how you might classify it	What senses could we use?	[Seeing, touching, smelling], hearing and tasting. Make it clear students will NOT be tasting the samples.
Discuss and emphasize resources they can use for help	What else can we use to help us decide?	[Class display board] [Journals] [Talk with partner]
Show students where to record their data on their sheets and let them know they need to explain their answers. Let them know it is ok if they are not sure. They can circle that response but need to explain why.	Is everyone clear so far? Any questions?
Set guidelines: walk from station to station demonstrating how to Keep the areas clean Keep substances on their trays Use the broom and dustpan for spills Throw away the toothpick after observing toothpaste Only use the pointer finger to pick up shaving cream Wash hands	Are there any questions?
If there are no questions, designate partners and allow students to go to their stations
Circulate room to make sure that Students are applying the class definitions Students are recording their reasoning before moving on
Give a five (5) minute warning: Make sure that each pair is able to visit sand station before time is up
Have students come back to desks for discussion

Explanation Class discussion of substances at stations		Time:10 min
What the Teacher Will Do	Probing Questions	Student Responses Potential Misconceptions
Glook: Encourage discussion of alternate opinions Validate student thinking	Who circled solid? Why/ why not? Who circled liquid? Why/ why not? Who circled not sure? Why/ why not?	Solid because it isn’t like water. Liquid because it doesn’t hold its shape Could be both.
Toothpaste / Shaving Cream: Same as above	Same as above	Same as above
Discuss neither solid nor liquid: Affirm students’ good efforts of thinking and using the definitions Explain that some scientist agree that these three are tricky to sort into solids or liquids
Introduce term Colloids: Tiny pieces of solids mixed into liquid (brief)
Confirm that these three substances are not really solids or liquids, but wanted students to have a chance to discuss and think about the definitions—just like scientists.

Elaboration Discuss Sand		Time: 5 min
What the Teacher Will Do	Probing Questions	Student Responses Potential Misconceptions
Hold up sample of sand. Let them know that unlike the other three substances it does fit into one of the categories	Is this sand a solid or a liquid? What evidence did you find that sand is a solid / liquid? What is sand made out of? What did the sand look like through the magnifiers? Did each piece of sand hold its shape?	[Solid] Liquid Colloid It can be poured, there are lots of small parts, you can stick your finger through it Sand [Rocks] [Shells] Dirt Tiny pieces of sand / [rock] / [shells] / dirt [Yes] No
Remind students of the chalk from Activity #2.	Is a big piece of chalk a solid? When the chalk was broken into medium-sized pieces, was it still chalk? Was it a solid? Was it still a solid when it was broken up into small pieces? Tiny pieces? Powder?	Yes Yes Yes Yes Yes [Yes] Maybe Not Sure

Evaluation Discuss Powders / Recording in Journals		Time: 5 min
What the Teacher Will Do	Probing Questions	Student Responses Potential Misconceptions
Explain why powders are solids Hold up cup of baking soda and explain that it is like sand only the pieces are even smaller.
Pretend you are a person who thinks baking soda is a liquid	Explain to me what may be incorrect about the following statements: It seems like baking soda takes the shape of its container. It seems like you can stick your finger through the baking soda. It seems like it makes a puddle. It pours..	Each tiny piece holds its shape. You’re actually sticking your fingers between the tiny solids, not through them. Each tiny piece holds its shape and does not make a puddle. Liquids are not the only things that can be poured.
Have students add the Solid or Liquid? sheet to their journals.
Allow time for students to write in their journals. Have them pretend they are writing a letter to someone who doesn’t believe sand is a solid.	How could you convince that person that sand is a solid? What is the evidence?	Define both solids and liquids Sand is made up of tiny solids Each tiny piece holds its shape