earth systems everything matters - hospitals - research · 2018-10-08 · pre-lesson preparation:...

everything matters part 3: mixtures

EARTH SYSTEMS

ACHRI/DGS/KFK/080212/V1 DRAFT COPY • ©2011 Delta Garden Study.

Frameworks

sCIeNCeNS 1.6.1 Verify accuracy of observations.PS 5.7.1 Explain how a small number of naturally-occuring elements can result in the large variety of substances found in the world. PS 5.7.5 Demonstrate techniques for forming and separating mixtures.PS 5.7.6 Classify substances as elements, compounds, mixtures.NS 1.8.1 Justify conclusions based on appropriate and unbiased observations.

LaNGUaGe arTsOV 2.6.2 Establish purpose for listening.OV 2.7.2 Establish purpose for listening W 5.8.7 Write with and without prompts for a sustained period of time.

s objeCTIvesThe students will learn:

objeCTIve #1 To define mixtures.

objeCTIve #2 To differentiate homogeneous from heterogeneous mixtures.

objeCTIve #3 To create mixtures.

objeCTIve #4 To identify physical means of separating mixtures.

objeCTIve #5 To appropriately use verbal speaking skills in class discussion with the teacher and Garden Program Specialist.


EARTH SYSTEMS • Everything Matters, Part 3: Teachers’ Guide

Worki

ng amendments like compost into the soilis an example of forming mixtures.

overvIewMixtures, in addition to elements and compounds, represent the third substance that builds our universe. Mixtures are the result of the combination of two or more substances that retain their chemical properties. Those substances can be separated again through physical means. Mixtures are either homogeneous (evenly mixed) or heterogeneous (unevenly mixed).

GardeN aCTIvITIes▲s Plant, harvest and work in the garden following the

Garden Guide.

▲s Perform separation techniques using soil or sand and water.



TIps For THe CLassroomPre-lesson preparation:

1. Check with Garden Program Specialist to determine which activities will be conducted.

LessoN oUTLINe

activities estimated duration actual duration

in the classroom

▲s Offer the icebreaker

▲s Define mixtures; discuss homogenous and heterogeneous mixtures

5 minutes

10 minutes

in the garden ▲s Perform several separation techniques, especially settling and filtering

10 minutes

▲s Plant, harvest and work in the garden following the Garden Guide

15 minutes

back in the classroom

▲s Hand out Student Workbooks, review and assign “Take it Home Activity” as homework

5 minutes

TIps For THe GardeNPre-lesson preparation:

1. Prepare materials for activities. (See activities and materials list in Supporting Information for Teachers.)

2. Prepare to discuss examples of mixtures and separation methods in the garden.

3. Prepare a brief garden work activity for students in the garden working with mixtures (composting, adding amendments, watering, etc.)

classroommaterials needed

▲s Student Workbooks

gardenmaterials needed

▲s Materials for activities

▲s Garden tools appropriate for mixing and filtering (shovel, wheel borough, gloves, amendments, etc.)



LessoN pLaN

I. Start in the classrooma. Icebreaker

Ask the students: “What is the only letter that doesn’t appear on the periodic table?”

ANSWER: “J.”

b. present main Topic▲s Define mixtures. Explain homogenous and heterogeneous mixtures.

meeTs objeCTIves #1–2

II. Take class to the garden▲s Point to the compost bin in the garden. Explain how the mixture

was formed by mixing leaves, straw, kitchen scraps, and other organic material. Discuss whether the mixture is homogenous or heterogeneous. Discuss ways that certain substances within the compost could be separated and what ways separation could be accomplished.


▲s Conduct various activities to demonstrate separation techniques listed in the Supporting Information for Teachers. Discuss different examples of mixtures in the garden. Here are a few ideas:


▲✔ When mixing amendments such as manure and compost into garden beds, gardeners should make sure the mixture is homogenous. Why?

▲✔ The Rainwater Harvest Unit filters the water from the roof through a screen before it is collected in the tank. Why?

▲✔ When watering plants in the garden, not all of the water is taken up by the plants. On a hot day, what happens to some of that water sitting on the surface of the soil?

▲s Instruct students to work the soil by planting peppers. Explain how techniques such as cultivating, hoeing, digging, incorporating compost, etc. are techniques to form a mixture, a heterogeneous one in this case.

meeTs objeCTIve #3

▲s Plant, harvest and work in the garden following the Garden Guide. ▲s Taste available produce. Ask students for feedback.

III. Take class back to classroom▲s Hand out the Student Workbook as reference material and class

assignment. Review take it home activities and encourage students to do them.



sUpporTING INFormaTIoN For TeaCHers

baCkGroUNd

Mixtures can be separated into their individual components by using physical methods, i.e., no chemical reactions (bonding of atoms) are involved. Commonly used separation methods include evaporation, filtration, settling, magnetic attraction and chromatography. They can be easily modeled in an indoor or outdoor classroom setting.

1. evaporaTIoN (INsIde or oUTsIde)

materials needed ▲s water▲s sturdy paper

plate

▲s permanent marker

▲s watch

procedure

Instruct the students to pour a small amount of water (e.g., 1⁄8 to 1⁄4 cup) onto the paper plate. Place in a warm, sunny spot. Trace the outline of the water puddle with a sharpie or marker. Observe and time how long it takes for the water to evaporate. You may wish to mark the shrinking puddle in regular intervals.

2. FILTraTIoN

materials needed ▲s Shovel▲s Wheel borough▲s Compost (from compost bin)▲s Filtration screen (preferably chicken wire)

procedure

Filtered compost can be added to potting soil and any remains in the filter (larger leaves, sticks, and other particles) can be put back in the compost bin to continue breaking down.

Have two students hold the filtration screen taut over the wheel borough. Instruct another student to pour a shovel full of compost onto the filtering screen. Ask other students wearing gloves to move the compost mixture across the screen until the finer compost has fallen through the screen and larger particles (leaves, sticks, etc.) are left on top of the screen. Use the compost in potting soil or garden beds. Put remaining

large particles back in compost bin to continue breaking down.

Observe and discuss the difference between the two separated substances. How do they compare to the original components? Could the compost be filtered even more? How? As a gardener, what would be the advantages and/or disadvantages of doing this?

▲✚ The following activities can be used as enrichment or a follow up:

1. seTTLING

materials needed ▲s Water▲s Jar with a lid▲s Two or more soil substances or

amendments (compost, perlite, silt, sand, clay, rocks, etc.)

procedure

Mix the different soil substances in a large jar. Instruct students to fill the rest of the jar with water, put the lid on tightly, and mix the substances my shaking the jar. Set the jar aside for about 30-45 minutes.

Return to the jar and examine the settling patterns. Water should settle to the top with lighter materials (sticks, leaves, etc.) floating at the top. Compost and silt should settle somewhere in the middle. Sand, clay, and rocks should settle down to the bottom. The layers should display a settling pattern that occurs due to the variance in density between the substances.

Observe and discuss the settling. Why did substances settle at certain levels? How could this process of settling be useful for gardeners?

2. maGNeTIC aTTraCTIoN

materials needed▲s a mixture of sand and small iron nails,

washers, screws or similar▲s magnet

procedure

Instruct the students to slowly pass the magnet over the sand and nails mixture. Observe and discuss how the magnet pulls out the items containing iron.



soUrCes

Science, Level GreenNational Geographic, green.msscience.com, Glencoe Science. The McGraw-Hill Companies, 2005

jefferson Labhttp://education.jlab.org/qa/atom_idx.html

oracle Thinkquest education Foundationhttp://library.thinkquest.org/C004647/chem/mixtures3.html

Chem4kids.comhttp://www.chem4kids.com/index.html

How to do Thingshttp://www.howtodothings.com/education/how-to-make-a-model-of-a-salt-crystal

Infoplease.comhttp://www.infoplease.com/ce6/sci/A0857504.html

explain That stuff.comhttp://www.explainthatstuff.com/atoms.html

kimball’s biology pageshttp://users.rcn.com/jkimball.ma.ultranet/BiologyPages/E/Elements.html

ehow.comhttp://www.ehow.com/how_5711733_measure-solubility-science-project.html#ixzz1AYZyc7Jz; http://www.ehow.com/how_4487842_make-model-molecular-structure-water.html#ixzz19vXbcoqi

Talking Yard, Naturally! By Betty Deere, Pulaski County Master Minutes, September 2008, Arkansas Cooperative Extension Service, Pulaski County Office

365 Outdoor ActivitiesPublications International, Ltd., 2001

The Vegetable Gardner’s BibleEdward C. Smith, 2009, Storey Publishing

separating mixtures http://antoine.frostburg.edu/chem/senese/101/matter/separation.shtml

mixtures and Compoundshttp://users.rcn.com/jkimball.ma.ultranet/BiologyPages/M/Mixtures.html

Types of mixtureshttp://www.saskschools.ca/curr_content/science10/unita/redon12.html

mixtureshttp://www.elmhurst.edu/~chm/vchembook/106Amixture.html

everything matters part 3: mixtures

EARTH SYSTEMS


study guide for studentsHave you ever swallowed ocean water? Salty, isn’t it? Salt water, which you can mix at home using water and table salt, is a mixture. Mixtures represent the third substance that builds our universe. (You’ve already studied the other two—elements and compounds.) With mixtures, you take two components, combine them to form some new substance, and then you can do something to take two components apart again. That means that unlike compounds, mixtures consist of components that retain their chemical properties. Their atoms don’t chemically bond through sharing or transferring electrons. When you apply certain physical processes such as boiling, changing pressure, cooling or sorting, you can separate mixtures back into their individual components.

The classic examples are concrete and salt water. Concrete is made by combining lime, water, sand and ground-up gravel and other rocks. As it hardens, it becomes solid. However, you can take a jackhammer and other tools to break it up again. It takes labor and time, but eventually, you could grind up all the pieces and start over again. It is similar with salt water. Boil off the water and you have the two original components: water molecules in the form of vapor and salt left at the bottom of the pan.

Mixtures can be solids, liquids, gases or even a combination of them. The air you breathe is a mixture, a combination of nitrogen, oxygen and other gases.

Mixture components can be evenly or unevenly mixed. Sweet tea is an evenly mixed or homogenous mixture; the sugar has dissolved in the tea and you can’t see it. Contrast that with vegetable soup, where you can see bits of carrots, onions, celery, potatoes, etc. That is an unevenly mixed or heterogeneous mixture.

Remember that in order for something to be considered a mixture, its components must be able to be taken apart again by physical means, such as boiling, cooling or sorting. Here are few commonly used separating techniques:

evaporation

When a liquid turns to gas, it evaporates. It happens because atoms and molecules escape from the liquid and turn into gas. All liquids can evaporate at room temperature and normal air pressure, but evaporation happens faster with warmer liquids. You’ve probably seen a puddle of water “disappear” after it rains. That’s evaporation.

Continued next page


Page 2 EARTH SYSTEMS • Everything Matters, Part 3: Study Guide

magnetic attraction

Mixtures that contain iron, such as a salt-iron mixture, can be sorted by magnetic attraction. A magnet will attract and separate the iron pieces from the salt. If you drop sewing pins on the floor, you can pick them up easily by moving a large magnet over the area.

Filtration

This technique is used to separate a liquid from a solid. The mixture is filtered or sifted. For example, passing liquid through filter paper which allows liquid molecules to pass through and the filter paper catches the solids as residue. Another example is straining noodles from water. Spaghetti noodles are cooked by boiling them in water, but they need to be separated from the water by putting the mixture of water and noodles in a strainer. Then the water is filtered through the strainer, but the noodles stay in the strainer. Then you can eat them with tomato sauce.

settling

Some liquid mixtures will separate by themselves. That happens when the individual substances don’t blend unless they are constantly stirred. If you combine sand and water in a bowl, the sand will start settling as soon as you stop stirring. It’s the same with oil and water. When a glass filled with oil and water is left standing, the water molecules will sink to the bottom and the oil will float on top. That’s why many salad dressings require shaking before use.

heterogeneous unevenly mixed

homogeneous evenly mixed

evaporation to change from a liquid into a gas

filtration technique used to separate certain particles or substances from another substance

magnetic attraction technique used to sort mixtures containing metallic materials mixed in non-metallic materials

settling occurs when substances in a mixture do not mix well and the substance of greater density settles to the bottom


everything matters, part 3EARTH SYSTEMS

Aclass

assignment

PS 5.7.6 Classify substances as elements, compounds, mixtures

1. what’s the difference between homogeneous and heterogeneous mixtures? Give examples for each.

2. List the four commonly used methods for separating mixtures. provide one example of each.

Take it HomeA fresh green salad is an

example of a heterogeneous mixture. Eat one tonight with some fresh greens,

tomatoes and cucumbers!



Aclass

assignment

answer key

1. what’s the difference between homogeneous and heterogeneous mixtures? Give examples for each. Homogenous: evenly mixed: sweet iced tea

Heterogeneous: unevenly mixed: vegetable soup

2. List the four commonly used methods for separating mixtures. provide one example of each.Methods:

▲s evaporation

▲s magnetic attraction

▲s filtration

▲s settling

Examples will vary.



Bclass

assignment


1. what’s the difference between homogeneous and heterogeneous mixtures? Give examples for each.

2. List the four commonly used methods for separating mixtures. provide one example of each.






Bclass

assignment

answer key

1. what’s the difference between homogeneous and heterogeneous mixtures? Give examples for each. Homogenous: evenly mixed: sweet iced tea

Heterogeneous: unevenly mixed: vegetable soup

2. List the four commonly used methods for separating mixtures. provide one example of each.Methods:

▲s evaporation

▲s magnetic attraction

▲s filtration

▲s settling

Examples will vary.



Cclass

assignment


1. write a paragraph comparing and contrasting homogenous and heterogeneous mixtures. Give your own examples of each kind in your paragraph.






Cclass

assignment

answer key

1. write a paragraph comparing and contrasting homogenous and heterogeneous mixtures. Give your own examples of each kind in your paragraph. Answers may vary. Examples may include: A homogenous mixture is a mixture that has been evenly mixed. An example is sweet iced tea where you would mix the tea with the sugar. A heterogenous mixture is one that is unevenly mixed. This mixture may have multiple ingredients that never fully combine. An example might be vegtetable soup where you have big chunks of potatoes, carrots etc. , mixed in with the broth.

earth systems everything matters - hospitals - research · 2018-10-08 · pre-lesson preparation:...

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