“Connecting Thin Film Deposition to Growing Crystal Rock Candy”
Crystal J. Woods, Algebra I,
Conrad High School STEM Academy
Dallas, TX
TEKS Covered:
A1.A, A.1B, A.1C, A.1D, A.1E, A.2C, A.2D, A.3A, A.3B, A.5A, A.5C,
A.6A, 8.8C
Real-World Connection:
Growth of Thin Film Deposition: The process of growing layers of metal on
a substrate or template. It serves one or multiple physical purposes including
protection, decoration, conducting, reflection, data storage, insulation, etc.
Introduction: Discussion of why crystals are important? Why are they
used? How does the real world use them? What devices students use that
involves the use of a crystal?
Driving Question: A competition: Why should we buy your crystals? Each
group will have to present all data (measurements used and why, graphs,
tables, equations, and verbal description) and create an advertising ad as to
why their product should be used? How can the solubility chart help you
produce cost effective crystals?
Objective:
Students will be able to describe and understand a functional relationship in
a variety of ways; analyze data from graphs to make predictions and
decisions; measure the growth of the crystals; connect the growth rate of
crystals to slope (rate of change); and make predictions and decisions
regarding the growth of the rock candy.
Parameters of Experiment:
Temperature (Various)
Amount of sugar (According to solubility chart)
Type of sugar (white, brown, sweeter (sugar substitute), and corn syrup)
Type of substrate (Wood and yarn)
Materials Required:
Water
Salt
Sugar, white (sucrose), brown sugar (sucrose), sugar substitute (dextrose),
corn syrup (fructose)
Food coloring
Glass jar
Beaker
Bowl (ice)
Skewer stick
Yarn
Wooden clothespin
Hot plate
Paper towels
Measuring cups
Solubility chart for sugar
Thermometer
Calipers
Procedures for growing crystals:
http://www.squidoo.com/makerockcandy
http://chemistry.about.com/od/growingcrystals/Growing_Crystals.htm
Engagement Sequence and Time Expectations:
Day 1 Introduction, Discuss Competition, Discuss solubility chart of sugar,
Supersaturated, and Review Crystal Growing Process
Day 2 Students will start crystal growing process (Teacher will assist with
using boiling water). Prepare container to grow crystals using all four types
of sugar.
Day 3 – Day 7 Students will individually record the assigned parameters of
experiment.
Day 8-11 Students prepare presentation
(Within their assigned group, students will need to discuss each individual’s
data collected and discuss how they are going to present the following:
****Required documents at the end of Crystal Growing Process:
 Journal Entries Day 1 through Day 7 (Monitoring Growth of Crystals)
 Collected data as a table
 Collected data as a graph
 Collected data as a functional relationship
 All justifications of measurements, predictions, and decisions made
according to measurements and solubility chart of sugar
 Advertisement for their product
 Discoveries made during experiment
 Presentation styles (PowerPoints are encourage), but not mandatory
Day 12-14 Groups will present crystal rock candy project
Grouping:
In your group of four, each student will be responsible for recording the
following:
 Temperature (FOR EACH INDIVIDUAL SETUP)
 Color (FOR EACH INDIVIDUAL SETUP)
 Amount of sugar used (FOR EACH INDIVIDUAL SETUP)
 Amount of water used (FOR EACH INDIVIDUAL SETUP)
 Measurement: Original thickness of substrate (stick or yarn)
 Measurement: Thickness of crystals (DAILY*FOR EACH
INDIVIDUAL SETUP)
**** EACH STUDENT IS RESPONSIBLE FOR MAINATAINING
HIS OR HER JOURNAL FOR EACH PARAMETER.
Extensions:
All groups will analyze and determine what factors they can change to
improve their product (i.e.…speeding up the growth of crystals)
Each group will conduct a “world tour” of the other crystal products, analyze
growth rate, and compare/contrast the results using the different parameters.
Name ________________ Lab Sheet Data
Group________________
Assigned Crystal Growing Process:
(Setup 1)
Type of Substrate:
Type of Sugar:
Amount of sugar used:
Amount of water used:
Any observations, discoveries, thoughts, and/or suggestions:
(Setup 2)
Type of Substrate:
Type of Sugar:
Amount of sugar used:
Amount of water used:
Any observations, discoveries, thoughts, and/or suggestions:
(Setup 3)
Type of Substrate:
Type of Sugar:
Amount of sugar used:
Amount of water used:
Any observations, discoveries, thoughts, and/or suggestions:
(Setup 4)
Type of Substrate:
Type of Sugar:
Amount of sugar used:
Amount of water used:
Any observations, discoveries, thoughts, and/or suggestions:
Observations
Preparation Day of solution
Measurement (Thickness of stick or yarn):
Day 1 after solution has been made
Temperature:
Color:
Describe the amount of solution remaining in jar:
Measurement: Thickness of Crystal:
Other Observations:
Day 2 after solution has been made
Temperature:
Color:
Describe the amount of solution remaining in jar:
Measurement: Thickness of Crystal:
Other Observations:
Day 3 after solution has been made
Temperature:
Color:
Describe the amount of solution remaining in jar:
Measurement: Thickness of Crystal:
Other Observations:
Day 4 after solution has been made
Temperature:
Color:
Describe the amount of solution remaining in jar:
Measurement: Thickness of Crystal:
Other Observations:
Day 5 after solution has been made
Temperature:
Color:
Describe the amount of solution remaining in jar:
Measurement: Thickness of Crystal:
Other Observations:
Day 6 after solution has been made
Temperature:
Color:
Describe the amount of solution remaining in jar:
Measurement: Thickness of Crystal:
Other Observations:
Day 7 after solution has been made
Temperature:
Color:
Describe the amount of solution remaining in jar:
Measurement: Thickness of Crystal:
Other Observations: