The Arizona STEM Acceleration Project
GROWING CRYSTALS PART 2:
Actualizing the Formation of Crystalline Solid
Blue, Green, Purple Growing Crystals
Growing Crystals: Actualizing the Formation of Crystalline Solid
Part 1
A 9th-12th grade STEM lesson
Maria Theresa A. Gonzaga
3/26/2023
3
Notes for teachers
Context:
List of Materials
Chemicals:
Copper Sulfate Potassium ferricyanide
Magnesium Sulfate Potassium Chromium sulfate
Food dye
Apparatus or Equipment:
500 mL Beaker Hot Plate Digital Thermometer
Stirring Rod Gloves Heat-resistant gloves
Beaker Tongs Weighing scale
For Molding:
Pipe cleaners/chenille stems Skewer/Suspender String
Alternative Materials:
String/ molder cups small bowl Popsicle stirrer
Arizona Science Standards
Arizona ELA Standards
Essential HS.P1U1.2
Develop and use models for the transfer or sharing of electrons to predict the formation of ions, molecules, and compounds in both natural and synthetic processes.
Plus HS+C.P1U1.4
Develop and use models to predict and explain forces within and between molecules.
Plus HS+C.P1U1.5
Plan and carry out investigations to test predictions of the outcomes of various reactions, based on patterns of physical and chemical properties.
Core Science Idea
P1: All matter in the Universe is made of very small particles.
9-10.W.7 Conduct short as well as more sustained research projects to answer a question (including a self‐generated question) or solve a problem; narrow or broaden the inquiry when appropriate; synthesize multiple sources on the subject, demonstrating understanding of the subject under investigation.
9-10.W.1 Write arguments to support claims in an analysis of substantive topics or texts, using valid reasoning and relevant and sufficient evidence.
a. Introduce precise claim(s), distinguish the claim(s) from alternate or opposing claims, and create an organization that establishes clear relationships among claim(s), counterclaims, reasons, and evidence.
b. Develop claim(s) and counterclaims fairly, supplying evidence for each while pointing out the strengths and limitations of both in a manner that anticipates the audience’s knowledge level and concerns.
e. Provide a concluding statement or section that follows from and supports the argument presented.
Arizona Science Standards
Cross-Cutting Concepts
Systems and System Models:
● Let the students create a well-defined system to focus on.
● Allow the students to design models (e.g., physical, mathematical, computer models) that can be used to simulate systems and interactions—including energy, matter, and information flows—within and between systems at different scales.
Patterns:
● Let the student identify different patterns to be observed at each of the scales at which a system is studied and can provide evidence for causality in explanations of phenomena.
● Empirical evidence is needed to identify patterns.
Stability and Change:
● Much of science deals with constructing explanations of how things change and how they remain stable.
Arizona Science Standards
Science and Engineering Practices
Asking Questions and Defining Problems:
● Provide questions that arise from careful observation of phenomena, models, theory, or unexpected results.
● Provide questions that require relevant empirical evidence to answer.
● Provide questions that determine relationships, trends and factors affecting the change including quantitative and qualitative relationships.
Developing and Using Models:
● Let the students use diversified or explicit models that best represent and support an understanding of phenomena.
● Let the students develop, revise, and use models to predict and support explanations of relationships between systems or between components of a system.
Objective(s): At the end of the 70-minutes lesson the students are expected to:
determine whether these substances are crystals based on their physical properties.
3. Use mathematics and computational thinking to explain how the amount of impurities are
used in producing crystals.
Agenda (70 minutes)
Experimental design: Students will make mini-crystal tree using the blue, green, purple and red growing crystals, timing and measuring growth are considered. They will graph this growth.
Poster Presentations: Students will demonstrate their understanding of how forces of attraction and measuring the amount of impurities of the substance influence the formation of crystals .
Peer Evaluations: Incorporates student-centered instruction encouraging peer teaching through Open House - Display, Present and React.
Vocabulary
Molecule: a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound
that can take part in a chemical reaction.
Nucleation: an initial process that occurs in the formation of a crystal from a solution, a liquid, or a vapour, in which
a small number of ions, atoms, or molecules become arranged in a pattern characteristic of a crystalline
solid, forming a site upon which additional particles are deposited.
Recrystallization: a solution is created by dissolving a solute in a solvent at or near its boiling point.
Supersaturated solution: a solution that has been heated in order to dissolve more material than would be possible
at room temperature.
Intro
“Are crystals formed naturally and synthetically similar? or different? Can you tell?”
Direction: From the 2 crystals given, Identify which crystal is a natural made and which one is synthetic. Compare and contrast the differences and similarities of the two.Use the Diamond diagram, write at least 2 observation for each.
Natural-made
Synthetic
Similarities
How do Crystals formed?
Factors affecting the formation of crystals:
Hands-on Activity Instructions
APPARATUS AND EQUIPMENTS
Chemicals:
Copper Sulfate Potassium ferricyanide
Magnesium Sulfate Potassium Chromium SO4
Equipment:
String/ molder Food coloring 600 mL Beaker
4 cups small bowl Hotplate
flower wire Thermometer Tongs
Stirrer Holder/Suspender/skewer
Safety First! Do the activity with care and safety, wear
gloves, aprons and proper disposals.
PROCEDURE:
Step 1. Make a Saturated Potassium ferricyanide Solution. Put 100 mL to 115 mL water EXACTLY to heat for 7-10 minutes but not in a boiling point.
Steps 2. In the beaker, ADD 1-2 tbsp. of Potassium ferricyanide with 100 mL cup and drop/slide the magnetic stirrer to stir for at least two minutes. TAKE IT OUT from the hot plate and let it cool for 2-3 minutes. This creates a saturated solution, meaning no more salt can dissolve in the water.
Step 3. Place the cooled beaker back again in a pot to heat or until boil for 5 minutes. Add and stir 1-2 tbsp. of potassium ferricyanide GRADUALLY to the solution. Put to boil for 5 minutes and continue stirring until you see THAT ALL OF IT dissolve in the solution.
LET IT COOL AND TRANSFER TO THE CUP.
Hands-on Activity Instructions
Step 4. Grow a Seed Crystal
Pour a little of the saturated borax solution into a cup or dish. Allow it to sit in an undisturbed location for several hours or overnight.
Step 5. Growing a Large Crystal
Tie the string or molder to the suspender or holder and leave it inside the solution. Place the jar in a location where it won't be disturbed. You can set a coffee filter or paper towel over the top of the container, but allow air circulation so that the liquid can evaporate.
Step 6. Do the same with the other chemicals
Follow the same procedures.
Check the growth of your crystal each day. If you see crystals starting to grow on the bottom, sides, or top of the container then remove the seed crystal and suspend it in a clean jar. Pour the solution into this jar. You don't want 'extra' crystals growing because they will compete with your crystal and will slow its growth.
Assessment
Students will be assessed according to the following:
Experimental design: They will make mini-crystal tree using the blue, green, purple and red growing crystals, timing and measuring growth are considered. They will graph this growth.
Poster Presentations: They will demonstrate their understanding of how forces of attraction and measuring the amount of impurities of the substance influence the formation of crystals .
Peer Evaluations: Encourage peer teaching through Open House - Display, Present and React.
Differentiation
TYING IT ALL TOGETHER:
For Visuals learner: Let them take a picture and make a picture frame with the most creative angle and subject focus.
For Kinesthetic learner: Let them do the tree frame as to their desired design.
For music/poetic inclined: let them make a poem or a song lyrics about crystals.
For ELL: Using a videodisc segment, students will explain sources of crystals/minerals and their uses in their languages.
Remediation
Extension/Enrichment
Let them use copper sulfate seeds crystal, will melt it and observe re -crystallization patterns.
Designs of these patterns will be reproduced in color after observing them through filters.
Let them try grow crystals under different conditions with alum and household items such as magnesium sulfate (epsom salt) measuring growth rate and comparing that rate under different conditions.