Matter - Properties and Changes
Guiding Question
How do we classify a proprieties of matter as physical or chemical?
Properties of Matter
Lab: How We Classify Matter
How do we classify different kinds of matter? How do the different elements in a material determine its properties? How can the way kinds of matter are combined impact the properties of the material? How can energy change the properties of a material?
LEARNING TARGETS
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To assess prior knowledge of students.
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Practice classifying and justifying (critical thinking).
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Introduce students to the systems we use for the classification of matter
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To develop an understanding of how the composition and thermal energy of matter impact its properties
Lab: Classification by Physical Properties
Using some common metallic and nonmetallic elements how can you determine their characteristic properties? How do you know when something is a metal? How do you know if it is a nonmetal?
LEARNING TARGETS
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To understand how scientists use patterns as a basis for classification systems
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To develop understanding of the identifying characteristics of metals and nonmetals.
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To generate interest in types and properties of materials.
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Practice classifying and justifying (critical thinking)
Changes in Matter
Lab: A Tasty Change: Cornstarch Chocolate Pudding
How can a little heat change the properties of a substance? Is the change physical or chemical? Are you sure?
In this lab you will be experimenting with the ratio of water to cornstarch for gel formation. Your objective is to determine the perfect ratio for making pudding, and then using your results to create a tasty treat!
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LEARNING TARGETS
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To understand physical changes in matter
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To understand chemical changes in matter
In Class Activity: Free Write/Class Brainstorm: Pysical vs. Chemical Changes
List anything and everything you know about these two categories of change including definition, description, properties, examples of the change, uses of the change, etc.
Lab: Physical or Chemical Change ID Lab
How do we decide what kind of change has ocoured in a material?
LEARNING TARGETS
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To assess prior knowledge of students.
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To generate interest in types and properties of change in materials.
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To help students develop their own definition/description of physical and chemical change.
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Practice classifying and justifying (critical thinking).
Mixtures of Matter
Lab: Growing Single Crystals
Ever want to grow crystals? Well now's your chance. During the course of this lab you will be growing your own large single crystals of copper sulphate.
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Safety Concerns: In order to understand how crystals form, we will grow crystals in the lab using a chemical called copper sulfate. Copper sulfate is used as a fungicide, herbicide, and pesticide. It is not to be ingested and is a skin irritant. Safety glasses and gloves should be worn throughout this lab to protect your eyes and skin. Wash your hands immediately after working in the lab. Any horseplay will result in immediate removal from the lab and you will receive no credit for doing this activity until you come in and make up the lab on your own time
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LEARNING TARGETS
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Develop an understanding of crystal growth, noting that under specific conditions, some materials can spontaneously assemble into organized structures.
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Generate an understanding of self-assembly during the process of growing crystals.
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Apply the process skills of scientific inquiry during experimentation.
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Determine the difference in formation between amorphous vs. crystalline structure.
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For some great pointers on growing beautiful single crystals CLICK HERE to go to the US Crystal Growing Competition website were they have written instructions as well as videos to help you grow your awesome crystals
We will be having our own competition in this class as well. There will be three categories.
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Highest Quality (best shape and clarity)
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Largest Crystal
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Coolest Crystal
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During this lab you are aloud to take pictures at any time; either for your data sheet instead of drawing, or you can send the pictures to me and I will post them to the website!
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Copper Sulphate Safety Procedures
Growing Copper Sulphate Seed Crystals
Copper Sulphate CuSO4 Crystalline Lattice Structure
Bonding Info
Copper sulphate is an ionic bond between a transition metal (copper) and a nonmetal (sulfur). Sulphate takes two Copper atoms and gains a negative valence charge, whereas the Copper gains a positive valence charge. The Sulphate is covalently bonded to Oxygen in a polar covalent bond with Oxygen having the higher electonegativity, and therefore pulling the electrons closer to its nucleus than to Sulfur's nucleus.
Why we place the seed crystal growing solution on an insulating surface
From the same initial copper sulphate solution of 0.43 g/mL
When placed on a non insulating surface (lab station), many small crystals develop due to an increased cooling rate
When placed on an insulating surface (blanket), only a few large crystals develop due to the slowed cooling rate.
WHY? As our supersaturated solution cools less copper sulphate can remain dissolved by the water. the slower cooling rate allows the molecules to organize on the already existing faces of the crystals where as quick cooling forces them to drop out of solution quickly, thus forming many small crystals.
Slower growth also results in purer crystals as the molecular geometry of the impurities will be different than the that of the molecule from which the crystal is forming. Impurities may attach briefly to a growing crystal lattice, but are unlikely to remain there as their structure does not match the crystal lattice. with crystals that form quickly these impurities become trapped, resulting in less pure crystals.
Making Observations
These are the observations you should be recording on your crystals each day. Below each observation category is written exactly what you need to include in your recordings. you may include more information if you choose. the button above connects to a word document you can use to record your observations.
use the scales that read two places past the deci-mal
Our crystal growing arrangement: a clear container for the solution with a popsicle-stick to span the opening, and from which hangs the crystal, suspended on a piece of thin copper wire (or string)
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Happy crystallographers!!!
