Using Classroom Assessment Techniques to assess the effectiveness of crystal growing in student research David McDonald Sidney High School.

Using Classroom Assessment Techniques to assess the effectiveness of crystal

growing in student research

David McDonald

Sidney High School

Non-Integer Crystals

• Ferroelectric Non-Integer crystals– We used the KDP KH2PO4 family of crystals– Largest crystal grown is in the 700 lb range at Lawrence Livermore National Laboratory

used in the National Ignition Facility (a giant laser)• We grew

K1-xNaxH2PO4

such as K.8Na.2H2PO4,K1-xLixKH2PO4

such as K.3Li.7H2PO4

• Other Ferroelectric crystals of interest(K.5La.5)TiO3 PMN (lead-magnesium niobate) PbMg1/3Nb2/3O3

The platinum 1-D complex K2Pt(CN)4Br.3

.3H2O

How to balance a chemical reaction with Non-Integer Crystals

• algebraic method__K2CO3 + __Na2CO3 + __H3PO4 __K1-xNaxH2PO4 + __CO2 + __H2O

6K2CO3 + 4Na2CO3 + 20H3PO4 20K.6Na.4H2PO4 + 10CO2 + 10H2O

A handout with problems and sample solutions will be available.

Extra Credit: Baking soda + vinegar -->

Growing crystals by evaporation

• Non-integer ferroelectric water-soluble crystals

of the KDP (KH2PO4) family

• Sidney High’s students and teachers have grown

K1-xNaxH2PO4

Rb1-xCsxH2PO4

K1-xLixH2PO4

• The crystals still to be grown

Rb1-x(NH4)xH2PO4

Rb1-xKxH2PO4

K1-xAgxH2PO4

Method of growing

• Using stoichiometry, the reactant amounts were calculated.• Using solubilities, the solutions were calculated and slowly mixed

together. The final solution was then left to slowly evaporate. • Students measured and graphed the actual solubility of new compound.

Solubility K1-xNaxH2PO4 S = 73.441x + 24.11

R2 = 0.8873

0

20

40

60

80

100

120

0 0.2 0.4 0.6 0.8 1

x value

So

lute

in

g p

er 1

00 m

l H

2O

Some crystal growers

Some data!

K.8Na.2H2PO4

with Ag painted electrodes

0

200000

400000

600000

800000

1000000

1200000

1400000

1600000

1800000

2000000

100.0 150.0 200.0 250.0 300.0 350.0

Temperature (K)

e ' (

rea

l pe

rmit

tiv

ity

)

Frequency10 7̂ Hz

Frequency10 6̂ Hz

Frequency10 5̂ Hz

Frequency10 4̂ Hz

Frequency10 3̂ Hz

Frequency10 2̂ Hz

CAT’s

Sorry, not this kind of cat!

• Classroom Assessment Techniques by Thomas Angelo & Patricia Cross2nd edition CR 1993ISBN 1-55542-500-3

• Techniques to allow teachers to become better observers of learning

• Examples of fifty different techniques

• NOTE: No special training need to carry out classroom assessment

Muddiest Point• What is the muddiest point or the most

confusing part of the "balancing chemical equations algebraically" idea?

• You have two minutes to respond and please use no more than one or two sentences. This is a way to assess how you are learning and not what you have learned. As we go through the semester there will be other types of assessment. This will allow you to focus more on your ability to learn and allow me to focus on the best methods to deliver the concepts.

• Thanks • Your Chemistry Coach

• Student responses to the Muddiest Point

• 1. Variables (61%)a. confusing Greek letter as variables

too many and what are they 22%“The whole idea, mostly the alpha, beta, and like signs and putting things where they are supposed to go.”b. What variable to solve for 22%>>> there is no definite letter to start with…c. Writing compound formulas 17%“I just hate converting the word equations to the symbolic equations. What is the symbol(s) for manganous?

• 2. Algebra (38%)a. Too many variables to solve for 6%“After you get the equations, when you are solving them I can never seem to do that right. “ I know how to solve equations but that part is the hardest.”b. Too many equations to solve for 17%“When I have to put all the symbols in one term.c. How to solve when you have more than one unknown 11%

Defining Features MatrixIn the following Matrix please categorize each situation as (+)-Safe or (o)-Unsafe.Situation Safe Unsafe

Walking into the lab (yesterday or today) without goggles to get your lab notebook

36% 64%

Leaving your ice cream spoon on the table 18% 82%

Pouring paper pulp down the sink 5% 95%

Using a chemical without reading the label 100%

Placing an unlabeled beaker on the counter by the window

100%

Noting water on the floor and telling your lab partner

86% 14%

Joking about drinking some of the chemicals that you are using

23% 77%

Place your nose close to the chemicals you are smelling

100%

Chewing gum in the lab area 18% 82%

Crystal project questionnaireScience research self-confidence survey Self-confidence Survey CAT #32

How confident are you??I feel confident...

Veryconfident

Confident Somewhatconfident

Not at allconfident

1. In learning new science related material

2. In using new ideas

3. In doing science research

4. In maintaining a research project

5. That doing a science project will increase my interest in science

6. That doing a science project will increase my desire to study science in college

7. That doing a science project will increase my enjoyment of science

8. That the crystal project was a success

Interest Survey CAT #34

Degree of agreement with the statementScience projects...

Strongly agree

Agree Somewhat agree

Do not agree

9. Develop a life-long love of learning

10. Develop an ability to think creatively

11. Improve science study skills and study habits

12. Improve academic study skills and study habits

13. Support the process of becoming a research scientist

14. Develop an ability to draw reasonable inferences from observations

15. Generate knowledge which breeds enthusiasm

16. Allow you to creatively apply prior knowledge to new situations

• 17. Give one or two examples of specific things your instructor does that really helped you learn chemistry while doing the crystal project.

• 18. Give one or two examples of specific things your instructor does that made it more difficult for you to learn chemistry while doing the crystal project.

• 19. Suggest one or two examples of specific practical changes your instructor can make that would help you improve your learning in this class.

• 20. CAT #13 – One sentence summary

• Describe in one sentence your feelings about the crystal research that you did last year in chemistry II.

• Answer the question who does what to whom, when, where, how & why?” then synthesize those answers into a single informational, grammatical, and long summary sentence.

Results from Survey!

• The Self-confidence Survey showed that the students were all either confident or very confident in working on science research or increasing their enjoyment of science.

• The Interest Survey showed the students agreed or strongly agreed that the science project improved their science skills and attitudes.

• 17. Give one or two examples of specific things your instructor does that really helped you learn chemistry while doing the crystal project.

• Mr. McDonald aided my learning in many ways. The first that comes to mind is record keeping. Before the crystal project, I would often do research and not record data very well. Through the crystal project I learned how important documentation is; not only for analysis, but also the upkeep of the crystal growth. Another thing that also comes to mind is preciseness. Mr. McDonald spent a lot of money on the raw chemicals, so we had to be careful and not waste any. By being careful, we had to keep a clean lab space and clean glassware (It was very easy to get a contaminate in the solution). Measurement also demanded perfection from us. We often checked the measurement many times.

• -- I learned how to keep a good record of my project, which I had never really done before. It is now an integral part of my current crystal growing in college. Along with that, I basically had to use basic trial and error experiments to make the crystals grow.

• he sends us in the right direction and lets learn as if we were the first ones doing the project so we have to learn the techniques in growing a crystal through experience.

• 18. Give one or two examples of specific things your instructor does that made it more difficult for you to learn chemistry while doing the crystal project.

I struggle to think of anything that Mr. McDonald did to make my learning more difficult. Often, we were on the same level as Mr. McDonald when we were growing never-before grown crystals. It would have been easier to know what is supposed to happen and when it should happen, but the nature of the project did not allow this. I would venture to say that both Mr. McDonald and we (students) learned a great deal through this project.

• 19. Suggest one or two examples of specific practical changes your instructor can make that would help you improve your learning in this class.

• I don’t know how practical it would be, but it would be beneficial to have more time. I think that if Chemistry II lasted two periods, it would be easier to learn and easier to do the project in itself. It would be nice if administration could make the Chemistry II class worth two credits and be scheduled in two consecutive periods.

• Perhaps just a little more discipline when we, the students, don't push ourselves.

• 20. CAT #13 – One sentence summary

Describe in one sentence your feelings about the crystal research that you did last year in chemistry II.

• I feel that last year I learned more about how crystals form, how the scientific process really works and how scientists learn more about how chemistry and the world really work.

• Chemistry II was one of the best classes I took during high school; I learned through practical and experimental means and I think the knowledge I’ve gained through the class will stick with me much more than if I would have simply read a book and took a test.

• Thanks to Murdock Charitable Trust grant summers 2001,2002

• Thanks to RET summer 2003

• Thanks to students in Chemistry II class 2002-2003