Lab Report Archives - Eva Varga


November 5, 2020

When An Experiment Fails

In our homeschool STEM Class, I attempted a little chemistry demonstration – just for fun.  I’d originally read about the pumpkin demo here, Rainbow Fire, and I did the experiment as described but as the kids can attest, it didn’t work. On the drive home, my kiddos hypothesized that the fact that I waited a little while for everyone to get settled may have caused the hand sanitizer to evaporate. Upon further investigation, however, perhaps I was missing a key chemical.  Another site I found, Green Fire, suggested the use of Heet (methanol).  I will have to try again.   If any of you give this a try, please let me know what you discover. 🙂

The fact that it didn’t work out though is perfect science (though very embarrassing when done as a class demonstration).  When an experiment doesn’t go as planned, however hard to admit, it is actually great.  It gives you the chance to go back and really figure it out.  There is always an answer for why it didn’t work. You often learn more when it doesn’t go as planned.

Later that afternoon, Buddy was working on an aeronautics project (he’s trying to make an airplane with cardboard, rubber bands, and plastic propellers).  When his design doesn’t work out, he gets very frustrated and laments, “I wasted so much time on this! I wasted all this glue!” (or tape, or whatever materials he used). It is difficult to console him but with my own failure earlier that morning, I had an example with which to show it happens to all of us.

Recently, another activity seemingly failed and I thought I would share our process of discovery with you …

Signs of Fall

One of the extension activities I had suggested to my STEM students when we were covering plants was a chromatography activity to investigate the pigments in leaves, Signs of Fall (scroll down for the activity “Invisible Changes”).  Another link, with the same title, Signs of Fall, provides a PDF download for a student page with guiding observation questions.

My daughter and I worked together to set up the investigation just as it was described.  She was even careful to measure an exact amount of isopropyl alcohol into each jar. We then placed a strip of coffee filter into each jar, taping it into place to secure it and then capping each jar with a small piece of aluminum foil.  We left it overnight but there was not a single strip with any color pigment.  We thereby walked away, shrugging our shoulders. Another failed experiment.  This was getting frustrating.

I couldn’t let this one go, however.  We must have overlooked something.  I thereby left it set up on the kitchen counter for another day or two while we contemplated and brainstormed what we might have done wrong. When we happened to peek into the jars a couple of days later, we surmised that perhaps we had put the coffee strips into the jars too soon – before the heat of the water bath had had time to activate the pigments because the liquid in the jars was now clearly colored when before it had remained clear.

We thereby pulled off the aluminum foil, discarded our first strips and inserted new ones.  We checked the progress of our test a few hours later …

When a Science Experiment Fails: Signs of Fall @EvaVarga.netWhoa-lah! 

If chromatography is something you’d like to investigate further, you might also consider this activity, Rainbow Candies: A Candy Chromatography Experiment for Kids.  It is a great way to use up some of that leftover Halloween candy that may be lying about.

Life Logic: BotanyAn expanded version of this lesson is available in the Science Logic curriculum
Life Logic:  Plenty O’Plants.



August 10, 2019

My daughter has been interested in engineering for as long as I can remember. She’s taken part in a numerous STEM workshops for girls over the years. Last summer, she had the amazing opportunity to take part in a summer intensive workshop (SESEY) at the university where she plans to enroll.

SESEY was created to encourage traditionally underrepresented groups to explore the world of engineering and to consider careers in its variety of fields. Initiated by Oregon State University in 1997, SESEY is coordinated by the School of Chemical, Biological and Environmental Engineering.

Working in the lab as part of her summer intensive workshop at Oregon State University

Participants have the opportunity to interact directly with university students – to ask questions about campus life and how to balance their course load. Presentations and tours of each department are provided to help students better understand the diverse options in engineering.

Learn how to encourage girls in STEM careers with these fun activities.

Best of all, participants have the unique experience of taking part in an authentic research project. Working in small groups, they apply the inquiry method to real life issues. At the end of the week, they present their findings in poster format at the annual DaVinci days celebration.

My daughter was overjoyed to be assigned to the one environmental engineering project this past year – Bioremediation of Chlorinated Solvents Using Aerobic Microorganisms. Here’s a peak at her poster:

The program – especially the professors and university student volunteers who collaborated to make it happen – has cemented her desire to pursue a career in chemical and environmental engineering. She will be applying for admission soon.

You might also be interested in the engineering unit I developed, World’s Tallest Buildings. This short unit study includes a timeline project, integrated writing assignment, and an oral presentation.

Have your teens taken part in summer learning experiences or weekend intensive courses? I would love to hear about opportunities in other parts of the country.



September 28, 2017

The Environmental Science merit badge has been a lot of fun to teach. In many ways, today’s activities were my favorite because they got us outdoors and we were able to visually see examples of local biodiversity, invasive species, erosion, and so much more. We concluded by discussing components of an environmental impact statement.

Today is the final post in the series highlighting the activities I have coordinated as the Environmental Science merit badge counselor for our local Boy Scout Troop.

Biodiversity & an Environmental Impact Statement @EvaVargaOur Local Biodiversity

For requirement #5, we chose two outdoor study areas that are very different from one another (a nearby forested woodland and an area of the sand dune undergoing succession). In small groups, the scouts marked off a study area with flags and counted the number of species found within. They then estimate how much space was occupied by each species and the type and number of nonplant species observed.

After our visit to each area, they were directed to write a report that discusses the biodiversity and population density of the chosen study areas. I look forward to reading their work and discussing what they learned from this experience one-on-one.

Environmental Impact Statements

Requirement #6 of the merit badge requirements is a little vague.

Using the construction project provided or a plan you create on your own, identify the items that would need to be included in an environmental impact statement for the project planned.

I do not know what construction project to which is referred so I was a bit confused. In my opinion, a local real-life construction project would be best suited for this requirement as the boys would have real experience and prior knowledge.

I thereby opted to take the boys for a walk around our neighborhood by which we were able to do several things:

  • visit a residential construction site and talk about the impact the housing development had on the local ecosystem (sand dune)
  • view, from a short distance, the north spit where a liquified natural gas (LNG) pipeline terminal has been proposed

Locally, there has been a HUGE political battle in regards to the LNG whereupon we could visually see the north spit where a liquified natural gas (LNG) pipeline terminal has been proposed. Along the way, we also observed areas disturbed by construction and thus an abundance of invasive plant species, an open meadow-like area (generally shrubs of both native and invasive species and a variety of wild grasses) the city presumably mowed to reduce wildfire danger, and the site where a WW2 bunker had been removed (this greatly saddened us but I believe the local authorities did so due to fear of litigation).

When we returned home, we discussed the impact the residential construction had on the area as well as the proposed LNG terminal. I pulled up the final Environmental Impact Statement that was released to the public and we walked through components of it for quite some time. It is rather lengthy – over 200 pages – so I aimed to summarize and pull out the key components including:

  • topographical maps
  • proposed roads
  • drafts of engineering plans for containment
  • mitigation plans

The previous posts in this series have touched on the following topics:

Environmental Policy Timeline, Key Terms, & Pollination

How Species Respond to Environmental Changes & Endangered Species

Acid Rain, Pollution Prevention, & Conservation Practices



September 17, 2017

What a joy teaching environmental science has been. Thus far, we’ve learned about the changes in environmental policy and how the Boy Scouts of America have contributed to environmental conservation practices. We have also learned about pollination, environmental changes, and threatened and endangered species.

Today, our focus shifts to acid rain, pollution prevention, and conservation practices we can engage in ourselves.

Each Sunday through the month of September, I will post a description of the activities I coordinated and the resources I used to teach the environmental science merit badge. Today’s post is the third in the series.

Pollution Prevention & Conservation Practices @EvaVarga.netWater Pollution – Oil Spill Activity

The Exxon Valdez oil spill occurred in Prince William Sound, Alaska, March 24, 1989, when an oil tanker bound for Long Beach, California, struck Prince William Sound’s Bligh Reef in the wee hours of ht morning and spilled over 10 million gallons of crude oil into the sea.

As the Scouts learned in the Environmental Science Timeline game we played the day prior, this disaster resulted in the International Maritime Organization introducing comprehensive marine pollution prevention rules through various conventions. We discussed this tragedy as I shared several photos and strategies that were used to clean up the oil.

We then engaged in an Oil Spill Experiment of our own. One Scout shared with us a video of an incredible new material – a foam material coated with oil-attracted silane molecules – that absorbs oil but not water. It was fascinating and extended our discussion.

Pollution Prevention & Conservation Practices @EvaVargaAir Pollution – Acid Rain Activity

Acid rain is a broad term that includes any form of precipitation (rain, snow, fog, hail, or even dust) with acidic components, such as sulfuric or nitric acid that fall to the ground from the atmosphere in wet or dry forms. With the aid of the visual above, we discussed the pathway by which precipitation becomes acidic.

While we didn’t undertake the lab outlined below due to time constraints, I encouraged each of the Scouts to set up the lab portion of the activity is to demonstrate the effects of acid rain on our environment.

Materials

  • Six Petri dishes (3 for the control, 3 for the acidic solution you choose to test)
  • Pipette
  • Large bell jar or similar item
  • Sulfuric acid or an alternative acidic solution (lactic acid – milk or a citric acid – lemon juice)
  • Two 2-liter soft drink containers
  • Four small pieces of marble or limestone
  • Small growing plant
  • Four small pieces of raw meat (fish or chicken)
  • Two green leaves
  • Small amount of soil

Procedure

Several days in advance, prepare Petri dishes with soil & stone, leaf, and raw meat (two dishes each). One set is to be the control to which distilled water is added. Add a solution of 50% sulfuric acid to the other set. Keep these in a location that is secure so they don’t accidentally get spilled.

Display the Petri dishes and show the class how the acid has affected soil/stone, plant, and animal materials compared to the items in plain water.  Together discuss what effects they think acid rain would have on the various aspects of their local ecosystem.

Set up the following long-term experiment:

  1. Place the potted plant under the bell jar and add a Petri dish or other small vessel of 10% sulfuric acid. Maintain plant normally including acid solution.
  2. Put about one inch of 10-15% sulfuric acid solution into one of the soft drink containers. Suspend a marble or limestone chip above the solution. Cap tightly.
  3. Duplicate (a) and (b) with water only as controls.
  4. Put a piece of raw meat in each of two Petri dishes; immerse one in water and cover, immerse the other in weak acid solution and cover. Note: these pieces of meat will
    deteriorate but the effect of the acid solution will become evident over a period of time.
reduce pollutionExcerpted from a slide show created by the Utah National Parks Council of the BSA

Pollution Prevention & Conservation

Lastly, we brainstormed a number of ways we could help to reduce pollution and conserve our natural resources. We filled the whiteboard with their ideas and discussed several in more depth.

Each Scout was then directed to choose two to put them into practice for the next couple of weeks. I asked that they keep track of their progress and to report back to me what they learned from the experience.


Join us next week for the final post in the series, whereupon I focus on an outdoor biodiversity study and an environmental impact statement.



March 25, 20161

bio plasticsPlastics play an important role in our lives.  Plastics are used to manufacture many everyday items and have significantly reduced the use of glass.  Some plastics are very durable and make things like furniture and appliances.  Other plastics make items such as diapers, trash bags, cups, utensils and medical devices.  The largest amount of plastic is used to make containers and packaging for items such as soft drink bottles, lids, shampoo bottles, etc. Common plastic is made from petroleum, a fossil fuel which is nonrenewable.

Nonrenewable resources are made naturally by the earth, but do not renew themselves fast enough to be able to count on having the resource for an indefinite period time.  Some resources are considered non-renewable because our access to the resource is limited.  For example, glass and metal are non-renewable resources.  The elements and minerals used to make glass and metal are found in the structure of the earth’s crust, however we are limited to what we can access through mining.

Renewable resources are either naturally reproduced at a sustainable rate or they can be produced in agriculture at a rate equivalent to the demand or need.  For example, corn can be used for ethanol fuel and to produce corn oil.  Corn is a renewable resource.

DIYBioPlasticsBioplastics are a type of plastic made from renewable, biological materials like starches, cellulose, oils or proteins. They generally contain little to no petroleum and therefore are usually biodegradable. When bioplastics are exposed to the environment (sunlight, heat, water, microorganisms) they breakdown into non-toxic compounds like carbon dioxide and water. Additionally, unlike petroleum-based plastics, bioplastics are made from renewable resources. These resources are typically agricultural byproducts, like cornstarch and potato starch, tapioca starch and casein (milk protein).

Biodegradable: refers to material capable of breaking down into harmless products through the action of living organisms or natural processes

Byproducts: in agriculture refers to secondary products created from a crop. For example, corn starch is a byproduct of corn

Make Your Own BioPlastics

Materials

  • Plant based oils (Corn Oil, Sesame Oil, Vegetable Oil)
  • Cornstarch
  • Water
  • Food coloring
  • Measuring spoons
  • Eyedropper (optional)
  • 1 Ziploc bag per student
  • Access to a microwave oven

BioPlasticsProcedure

  1. Place the following ingredients in a plastic bag: 1 tablespoon of cornstarch, 2 drops of oil, 1 tablespoon of water, and 2 drops of food coloring.
  2. Seal the bag and gently mix the cornstarch mixture by rubbing the outside of the bag with your fingers until combined.
  3. Open the bag slightly, making sure it can vent. Place the bag in a microwave oven on high for 20-25 seconds.
  4. Carefully remove the bag from the microwave and let it cool for a few minutes. While it is still warm, students can try to form their plastic into a ball. Observe what it does.
  5. Ask them to describe their plastic; did it turn out differently than others? Does the type of oil you used affect the bioplastic? Have the students name three things they could make with bioplastic.

Take it Further

I’m committed to sharing activities and resources for teaching science in your homeschool. I believe it is helpful to see that science isn’t scary and it doesn’t require special curriculum. Here are a few resources that you can use to further your study of plastics and renewable vs. nonrenewable resources.

Watch the 3-minute How Stuff Works video clip about Corn Plastic.

In this hands-on, inquiry based Plastics Lab Activity, students investigate whether all plastics the same? How are they different?

Polymers Are Cool ~ Experiment with different polymers, large molecules composed of many repeated subunits, with these 3 great recipes.

As plastics are not biodegradable, learn how you can make a difference in encouraging others to reduce our use of plastics. The volunteers at Washed Ashore inspired us to create a Bottle Cap Mural to help spread the word of the harm done to our oceans by plastics.

 



March 12, 2016

Most people don’t realize that the Sugar Maple is not the only tree that yields syrup. We had thoroughly enjoyed our first experience maple sugaring when the kids were toddlers. Now that we have returned to Oregon, we are delighted to revisit our sugaring experience with Tap My Trees.bigleafmaple

We received a Tap My Trees starter kit in exchange for an honest review. I also received monetary compensation for my time spent in reviewing the product.  All opinions expressed are true and completely our own. Please see my disclosure policy for more information.

There are 13 species of maple trees that grow in the United States. The Sugar Maple (Acer saccharin), one of America’s best-loved trees, is the most well known due to its historical and economical importance.In Oregon, Sugar Maple is an ornamental and found only on college campuses and occasionally in someone’s yard. Oregon’s most prevalent native maples are Bigleaf Maple (Acer macrophyllum) and Vine Maple (Acer circinatum). Learn more about Our Native Maples in my earlier post. 

bigleafOur Maple Sugaring Experience

I shared a more in-depth look at Science of Sugaring a few months ago. From everything we have read and from our past experiences, we knew that sap would immediately start to flow after tapping the tree if the weather conditions were just right. Cold nights and warm days were what we needed.

We waited. We watched the forecast. Then my dad telephoned, “This week looks to be a good time to go sugaring?!” Yippee! We gathered our gear and piled into his truck.

Oregon Geography

The Oregon Coast is bordered on the west by the Pacific Ocean and the Pacific Coast Mountain Range on the east. It is 30 to 60 miles (48 to 97 km) wide and averages around 1,500 feet (460 m) in elevation above sea level. Temperate rain forests with high peaks and steep ridges dominate this region.elliotstateforest

In the southernmost section of the Coast Range where we live, you can find the Elliott State Forest. The forest is home to over 50 mammal species, over 100 species of birds, and nearly 30 reptile or amphibian species that spend significant portions of their life cycle in the mountains. It is here that the Big Leaf and Vine Maples grow.

Tapping the Trees

It took about an hour to drive up to the forest and locate the Big Leaf Maples. We found a several in the mid elevations on relatively dry slopes. As the terrain is so steep, most were out of our reach but we did manage to find a couple near the road. Sadly, when we tapped them, the sap was not running. Dad said this was an ominous sign but we hung our bucket anyway and gave it a go.

rainforestWe then drove to a lower elevation in a narrow, moist valley where we located a grove of Vine Maple. You can see in the photo above the abundance of ferns and bryophytes in the understory. When we tapped the Vine Maple, the sap started flowing immediately.

Maple sap is a clear fluid and resembles water. The collection amount may vary. Some days you will collect only a small amount and other days your buckets may overflow if not emptied.

We thereby hung several bottles amongst the vine maple shrubs that covered the hillside. For these smaller trees, we recycled a plastic soda bottle by poking a hole in the side and sliding the bottle onto the spile.

vinemaple

Collecting the Sap

We returned a few days later to retrieve our materials and any sap we collected. Much to our chagrin, the bucket on the Big Leaf was dry. It was just the wrong time. We’ve wanted to try again but the weather hasn’t been very cooperative this year. We’ve had an unseasonably warm winter and lots of rain.

The vine maples, however, were more cooperative. We collected about a quart of sap which when processed yielded only about 2 tablespoons of syrup. Enough for one pancake serving anyway. We all agreed it was very similar to the pure syrup we purchase, but with a little more tangy taste.

It is clearly much more work and effort to tap trees in Oregon, thus making the endeavor economically disadvantageous. This is due in part to the difficulty in reaching the trees but also that a larger quantity of big leaf or vine maple sap is needed to produce equivalent volumes of syrup than the sugar maple.

However, I highly recommend the sugaring experience to families, especially if you have access to maple trees where you live. It is great opportunity to get outdoors and bond together over shared memories – not to mention all that one can learn through the process.

While 2016 wasn’t a good year for tapping the Big Leaf Maple in Oregon, we’ll be sure to try again next year. Sugaring has become a lifelong hobby everyone in our family enjoys.

Maple Sugaring with Tap My Trees

Tap My Trees is the #1 provider of sugaring supplies for the hobbyist. Devoted to educating families about the practice of maple sugaring Tap My Trees has made donations of supplies to nature centers hosting maple sugar events and they’ve made quite a few products available for teaching Maple Sugaring at Home.

They offer 4 starter kits with the highest quality supplies to tap maple trees at home. You can also customize your kits by ordering sugaring accessories individually. The instructive guidebook outlines the steps to making the maple sugar and contains all the information you need for a successful sugaring from identifying the appropriate tree to how weather affects the sap run, when to collect, and how to boil down the sap.

The lesson plans also include a timeline beginning in the winter and go month by month listing the topics for each month leading to the sap collection and syrup making. Sugaring is a fabulous unit study covering botany, ecology, meteorology, physics, and even history!

Connect with Tap My Trees

Tap My Trees is committed to sugaring education and they provide recipes and other information on social media. Their products are also available on Amazon, if you prefer. Be inspired!

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