The Arizona STEM Acceleration Project
GROWING CRYSTALS PART 1:
Actualizing the Formation of Crystalline Solid
Sugar Crystal Growing
Sodium tetraborate Crystal Growing
Growing Crystals Part 1: Actualizing the Formation of Crystalline Solid
A 9th-12th grade STEM lesson
Maria Theresa A. Gonzaga
3/26/2023
3
Notes for teachers
Context:
List of Materials
Sucrose (Table sugar) Sodium tetraborate (Borax)
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:
Agenda (Day 1 and Day 2 Lesson)
Day 1 (50-60 minutes)
Experimental design: Students understanding how to design their own desired crystals and distinguish factors that influence the formation of crystalline solids
Day 2 (50-60 minutes)
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:
Crystalline solids: a solid containing an internal pattern of molecules that is regular, repeated, and geometrically arranged.
Molecule: the smallest physical unit of a substance that can exist independently. A molecule is made up one or more atoms held together by chemical forces.
Supersaturated solution: a solution that has been heated in order to dissolve more material than would be possible at room temperature.
Forces of Attraction: refers any particular force that draws two objects or particles towards each other.
Chemical Bonding: the attraction between two or more atoms that allows them to be able to form a stable chemical compound.
Crystallization: the process by which solid forms, where the atoms or molecules are highly organized into a structure known as a crystal
Driving Question:
“Why can gems be crystals yet crystals cannot be gems? What makes the two differ?
Gems | Crystals |
| |
Using sample gemstones and crystals, sort and identify which is a crystal and a gemstone. Observe and compare the properties of the gems and crystals. Write your answers to the table provided.
DAY 1 (70 MINUTES)
What is a Crystalline Solid?
(a) ionic
(b) molecular
(c) metallic
(d) covalent network
(c ) metallic crystal: metal ions and delocalised electrons (d) covalent networks: network held together
Photo Credits: Classes of Crystalline Solids | CK-12 Foundation
11.7: Structures of Crystalline Solids - Chemistry LibreTexts
Your type of Crystal Structure!
Ionic crystals
Metallic crystal
Covalent network crystals
Molecular crystals
Dispersion forces - nonpolar crystals
Dipole-dipole forces- polar crystals
Hydrogen bonds - molecules held together
Let’s investigate!
In the conduct of the experiment, be guided with the following:
Hands-on Activity: Let’s grow crystals!
Materials for the Activity:
List of Materials
Sucrose (Table sugar) Disodium tetraborate (Borax)
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
Hands- on Instructions
Let’s Grow Crystals!
Step 1. Make a saturated solution
Make a saturated sugar solution. Put 200 mL water EXACTLY to heat for 5-7 minutes but not in a boiling point.
Step 2. Heating the solution
In the beaker, ADD 2 cups or 400 mL of sugar to the heated and stir for at least 3-5 minutes or until sugar dissolves.
Step 3. Cooling the solution
TAKE IT OUT from the hot plate and let it cool for 2-3 minutes. This creates a saturated solution, meaning no more solute can dissolve in the water.
Step 4.
Place the cooled beaker back again in a pot to heat or until boil for 3 minutes. Add and stir 1 and half cups or 260 mL of sugar GRADUALLY to the solution.
Activity Instructions:
Step 5.
Put to boil for 5 more minutes and continue stirring until you see THAT ALL OF IT dissolve in the solution.
LET IT COOL AND TRANSFER TO THE CUP.
Step 6. Grow a Crystal
Tie the string or molder to the suspender or holder and leave it inside the solution. Pour a little of the saturated solution into a cup or dish. Allow it to sit in an undisturbed location for several hours or overnight.
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.
Assessment Day 1:
Experimental design: Students understanding how to design their own desired crystals and distinguish factors that influence the formation of crystalline solids
Laboratory Worksheet:
Intro: What are the attractive forces that influence the bonding?
Watch the video about intermolecular forces and intramolecular forces to fully understand how crystalline solids are affected by bonding or particle interactions.
Relate the properties of different types of solids to the bonding or interactions among particles in these solids.
DAY 2 (60-70 minutes)
Poster Presentation:
From your the role assigned for each member of the group, Presenter will discuss and explain your understanding of how forces of attraction and measuring the amount of impurities of the substance influence the formation of crystals .
Assessment
Peer Evaluations: Incorporates student-centered instruction encouraging peer teaching through Open House - Display, Present and React.
OPEN HOUSE:
Display their work, present the process and outcome and reacts through post-it cards.
Liked emoji means they understand the process.
Heart emoji means they understand and explain the process on their own language.
Question mark means they need more help and have to write specific questions
towards their concern to help them more understand it.
Differentiation
Students will be in regular groupings but they will have a peer teaching and will have a modified rubric for assessment.
Remediation
Extension/Enrichment
ELL students may use internet and be in group that composed of bilingual members.
Labeled activity is used for them to understand terms.
Write arguments based on the emoji attached to the displays to support claims in an analysis of substantive topic 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 (CER)