Easy and Fun pH Lab

 

A simple pH lab is fun and easy to prepare. All you need are pH paper (purchased online), water (preferably distilled ), small containers, and a collection of household substances to test. Use this lab when teaching MS-PS1-2. Analyze and interpret data on the properties of substances before and after substances interact to determine if a chemical reaction has occurred. 

The lab procedure is simple. Pour a small amount of a water-based liquid into a container. You can test dry substances like baking soda by mixing them with water. Dip in the pH paper, and watch for a color change.

Students observe a color change when the pH indicator in the pH paper reacts with the substance being tested. After dipping the pH paper into the substance, the color of the paper is matched to a color chart that comes with the pH paper. 

You can invite students to bring to class substances that they would like to test. Here are examples of some that you might provide for students:

* Vinegar

* Rainwater

* Tap water

* Salt

* Baking soda

* Shampoo

* Borax

* Seltzer water

* Lemon juice

* Apple juice

I like the element of choice in this lab as students are free to test the substances that interest them the most. The teacher provides a collection of substances, adds any that students bring in from home, and then asks students to select a certain number to test. I required five. Students record their results on a simple data sheet. I did this lab at home with my eleven-year-old daughter just for fun, and she created her own data sheet.

Often a few students want to test their own spit. When I did the lab at home with my daughter, this was the first thing she wanted to try! If you choose to indulge your students' curiosity, you could give them a pH paper or two to take home.

When students have finished their tests, you can have them discuss their results. Which substances were acidic, basic, and neutral? Did students who tested the same substances get the same results? What might cause variation in their results? Do they notice any common properties of the acids? Did anyone test the pH of a mixture of more than one substance? If no one tried mixing an acid with a base, have someone try this to see the result.

This pH lab takes little set-up on the teacher's part. It's a fun way for students to become more familiar with the concept of pH and observe a color change in a chemical reaction.

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Springtime Science in the Garden: Plant "Cousins" and a Baby Skunk!

Mysterious holes were appearing in my garden plot. Sometimes I would find a plant or two pulled up, and sometimes not. Either way, the plant was thrown to the side and left untouched. Talk around the Juniper-Front Community Garden informed me that others were experiencing the same issue, and skunks were a principal suspect. This theory made sense to me because I had been seeing more skunks than usual in the neighborhood early in the morning. One morning I was a bit startled but also pretty excited to see a mama skunk with her nervous baby sneak into our garden through an opening in the concrete wall.

Although I was too intimidated to follow the skunks around and try to observe them actually digging the holes, some internet sources describing the kind of holes skunks dig (shallow with dirt tossed around them) made me think that they were likely responsible. It was frustrating to be losing plants after investing time, resources, and hope into my little seeds, but honestly, how could I stay mad at anything so cute as a baby skunk? 

The fight to save my plants sparked an interest in some informal experiments to deter the skunks. Would a tomato cage protect the plants? Are the skunks that gardeners suspect are digging up our plants more interested in compost containing eggshells? These experiments have not been strictly controlled, and they are ongoing and as yet inconclusive, but they are still interesting (when not too frustrating)!

Gardens are filled with opportunities for informal science education. Just digging around in the soil to weed, plant, or harvest leads to new discoveries.

Bringing students or my own child to spend time in a garden inevitably leads to new learning and a connection with the natural world. I've often been surprised at how excited middle school students get over finding a tiny insect, spider, or worm! Gardens attract pollinators and other wildlife that everyone enjoys experiencing.

Looking carefully at garden flowers is a nice springtime activity that can help you learn about plant families. I enjoy observing flowers as an adult, and children can be engaged this way, too. Did you know that tiny strawberry plants and tall apple trees are in the same plant family, meaning they are fairly closely related? Although a look at the entire plant would fool you into thinking otherwise, if you compare their flowers, you can see that their flower structure is very similar. Notice the similar structure of the strawberry and apple blossoms, including their five petals.

Strawberry Flower

Apple Blossoms Photo by Anastasiya Romanova on Unsplash

Both strawberry plants and apple trees are members of the rose family, Rosaceae. If you compare their blossoms with the photo of a wild rose below, you can see similarities, such as the number of petals.

Being in the same plant family means that the plants had a relatively recent common ancestor. How could the strawberry plant and apple tree evolve to be so very different while their flowers remained so similar? Natural selection favors traits that help a plant survive and reproduce. Traits such as growing tall could potentially be beneficial, but a change in the structure of a flower- the plant’s reproductive part- could render the plant unable to reproduce. Changes in flower structure are risky and could be an evolutionary dead end if the plant has no offspring. This is why flower structure stays more constant as other plant parts evolve over time, and why looking for similarities in flower structure gives us a window into the evolutionary history of the plant and helps us identify plant families.

Whether watching for pollinators and other wildlife, observing flowers, or just digging around, a garden in the springtime is well worth a visit!

If you are interested in reading my blogpost on summertime in the garden, follow this link:

Summertime Science in the Garden: Pollinators

If you would like to know how to help collect data on local pollinators, here is a blogpost about the Great Sunflower Project:

Get Outdoors with Citizen Science! The Great Sunflower Project

Michigan State University Extension has a webpage on skunk holes versus other holes in your garden or yard:

https://www.canr.msu.edu/news/whos_that_digging_in_my_yard_skunks_raccoons_or_moles

Thanks to Kerry Woods for sharing his vast knowledge and love of plants with me.

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Hexagonal Thinking: Connections and Discussion in Science Class

I first heard about hexagonal thinking when schools were closed due to the COVID pandemic, and I was looking for fresh ways of engaging students while teaching online- quite the challenge! Betsy Potash's interview on The Cult of Pedagogy Podcast caught my attention. She described her hexagonal thinking activities in which groups of students work together to find connections between different terms related to a central topic. While teaching virtually, I tried using hexagonal thinking to facilitate small-group discussions on the concept of evolution and natural selection. Its success lead me to continue using hexagonal thinking when our school reopened.

Using a hexagonal thinking activity at the end of a unit helps students pull all the ideas together and solidify their knowledge. The social aspect of the activity is another plus as students share their understanding of concepts with peers and learn from one another.

Students can engage in hexagonal thinking discussions using digital or print resources, which Betsy Potash offers for free on her website. I customized her resources for an end-of-unit discussion on evolution and natural selection that addressed these Next Generation Science Standards (NGSS): MS-LS1-4, MS-LS3-1, MS-LS4-4, and MS-LS4-6.

The goal of a hexagonal thinking discussion is for students to find connections between given terms, and to indicate these connections by placing hexagons with the terms beside one another. Betsy Potash's template allows you to fill in the terms you would like students to use for the activity. 

On her website, Betsy Potash gives an example of how to use hexagonal thinking to discuss climate change. I chose to use seven hexagons and the following terms for discussions on evolution and natural selection:

• Natural Selection

• Mutations

• Biodiversity

• Survival of the Fittest

• Inheritance of Traits

• Genes

• Variation

• Evolution

This image shows a slide from the template after I customized it:

In small groups, students discussed how to place the terms on the hexagons such that the terms on hexagons with connected sides related to one another. They then chose five of these connections to explain in writing. With seven available hexagons and eight terms, students were able to choose one term to leave out. 

I simplified the activity a bit by not using the arrows provided in the template. The arrows can be used by students to indicate which connections they will write about. Instead, I asked students to name the terms before describing the reasoning behind their decision to connect them.

As I circled around and observed student groups at work, I noticed how students assisted one another with remembering the meanings of terms. As they discussed which terms to connect, they reviewed much of the content of the unit and deepened their understanding.

My students used a digital version of the activity. I found it helpful to give direct instruction on how to drag and drop the terms using their Chromebook, and I included detailed directions for this on the slideshow. It was a little tricky for students at first, but everyone got the hand of it with practice.

Once students had completed the activity, I asked them to write both a self reflection and a group reflection to consider how they participated individually and how the group worked together. Announcing this at the beginning of the activity made expectations clear and helped students be mindful of their participation.

I found hexagonal thinking to be a great way for students to pull multiple ideas together and share their understanding with classmates at the end of a unit. 

If you are interested in learning more about hexagonal thinking, you can check out Betsy Potash's website, Spark Creativity, where she offers a free template for hexagonal thinking activities:

Spark Creativity

Here is a link to Betsy Potash's interview on The Cult of Pedagogy Podcast:

Betsy Potash Interview on Cult of Pedagogy  

Betsy Potash explains how to use hexagonal thinking in this short Edutopia video:

Using Hexagons to Build Critical Thinking Skills

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Model Photosynthesis and Respiration with Berries

 

Students can model photosynthesis and respiration by making molecules out of strawberries, blueberries, grapes, and toothpicks. I wanted to create a healthier option to the gumdrops that are often used to model molecules, so I experimented with berries, and it worked nicely! 

You can use this activity when teaching Next Generation Science Standard (NGSS) MS-LS1-6: Construct a scientific explanation based on evidence for the role of photosynthesis in the cycling of matter and flow of energy into and out of organisms. It can also be used to teach MS-LS2-3: Develop a model to describe the cycling of matter and flow of energy among living and nonliving parts of an ecosystem.

Students should prepare for this activity by first creating structural formulas for the reactants and products of photosynthesis and respiration. In a previous class, I provided a handout for students to draw structural formulas of all reactants and products of each process, referring students to this video (start at 6:10 for photosynthesis and 5:33 for respiration):

Chemistry Tutorial: Chemical Equations & Photosynthesis

As students draw their structural formulas, they begin to see that photosynthesis and respiration are opposite processes. 

On the day of the activity, students get directions for creating their berry models. Because carbon atoms are the largest of these atoms, I asked students to represent them using strawberries, the largest berries. The smallest atom, hydrogen, is represented by the smallest berry. Toothpicks are used as bonds.

Strawberries = Carbon Atoms

Grapes = Oxygen Atoms

Blueberries = Hydrogen Atoms

With the structural formulas they created previously in hand, students begin by creating molecules of water and carbon dioxide, the reactants of photosynthesis. You could allow students to work with a partner though you may want students to handle their own berries to prevent the spread of germs. The photo below shows students who successfully completed this first step (one water molecule not shown in the frame).

After building the reactants of photosynthesis, the next step is to model photosynthesis by breaking the bonds in water and carbon dioxide molecules and rearranging the atoms to form glucose, the product of photosynthesis.

The last step is to model respiration by breaking apart the glucose molecule to form the products of respiration, carbon dioxide and water. Students end with the same molecules they started with.

Once students have their hands-on work checked by a teacher and write about the relationship between photosynthesis and respiration, they can eat all the berries. One student told me afterward that she had never really “gotten photosynthesis and respiration” before but understood it now!

If you are interested in another activity that involves playing around with food in the name of science, follow this link to my previous blogpost on making models of cells using pasta and toppings:

Edible Cell Model Made of Pasta

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