“Chemistry is part of your everyday lives,” I tell my students on the first day of chemistry class. I aim to help them each truly understand and believe this comment by the time they leave my class.

In my experience, students often fear chemistry class. So, I tell them to think of chemistry as a foreign language. There will be many new things you will learn; some will be easier to understand than others. But in the end, if you commit to learning, you will become fluent in this new language. Topics like stoichiometry
and Le Chatelier’s Principle will seem second-nature once you’ve applied your knowledge to these new concepts. My approach helps students interpret stoichiometry as a fancy way to say “measuring elements,” and to translate the fancy French name as “all things balanced,” to name just a couple of examples. I want my students to be successful in my class — and one step at a time, they’ll realize this is definitely doable. 

As part of my introductory speech, I don’t downplay the difficulty of the content. Other sciences have their own difficulties, but it seems like there is always some content for students to relate to easily. Chemistry, on the other hand, is not only abstract, but also introduces new, foreign-sounding phrases and vocabulary like excited electrons, intermolecular forces, and stressed out systems. Because my goal is to make these concepts more familiar, I look for analogies students can relate to. For example, those excited electrons are responsible for the neon lights in New York City; you could not drink water if the atoms in it did not combine with each other and stay together; and Le Chatelier’s Principle will provide opportunities to analyze complex systems and teach students how to predict behavior— which I like to compare to a seesaw.   

Creating connections

As I introduce each new topic, I make sure to include something students are familiar with to help them see a connection from the very beginning. Using water and ice is a basic example when discussing physical properties and changes. Students place an ice cube in their hands and feel it melt. It’s either solid water or liquid water – no changes have occurred, even though the physical properties have changed. The experience is full of fundamental chemistry concepts which we will explore further and revisit throughout the year.

Whenever I can, I use a lab to connect with a new word or concept to bring it to life. For example, a lab on physical and chemical changes has students cut and burn paper — familiar concepts, yet now we can identify which changes are physical and which are chemical. The best part of the learning process for me is always the aha moment, when students truly see and understand what’s going on. I know that they’re not always going to remember what we read, or the examples from a specific unit, but I’m hoping they will remember the experiences — the labs, activities, and discussions — and realize how the chemistry involved is connected to their life.

I listen to student discussions so I can understand how they see things, and gain insights into the interpretations and connections that they are making. The examples that follow illustrate how I try to facilitate connections and understanding in my classroom.

Real-World Example 1: The Candle

Figure 1. In the author’s lab, a burning candle shows one type of chemical change as it disappears. The heat of the flame vaporizes the liquid wax (turning it into a hot gas) that forms right below the wick. The gas breaks down the compounds and the candle disappears.

A very simple bit of chemistry students have all been engaged in: birthday cake candles. I sometimes ask them: “Is the candle melting or is it burning?” The question seems so simple, yet the stumped looks on their faces tell me that it isn’t an easy question. I ask them to share their reason for choosing one answer over the other and, listening to their answers, it becomes obvious that there is truly some confusion.

Of course, students can see certain differences, such as when they’re asked to heat up and melt the candle only to see a pool of wax forming — clearly, a physical change. In contrast, when the candle wick is lit, the candle slowly disappears (as shown in Figure 1); because students can’t bring the candle back, they know it’s a chemical change. Understanding the difference between the two types of change is the aha moment for students. Once that is understood, we can get into the differences between physical and chemical changes. Students now have a real-world example they can relate to and, hopefully, fully understand! 

Real-World Example 2: The Electron

The next connection for students can fit in the palm of their hand; in fact, they’re practically attached to it. Students’ cell phones present a perfect way to discuss the importance of electrons in their everyday life.

I start by instructing students to pull down their shirt sleeve over their hand, and then try to write a text message. Nothing! So begin the discussions. Why? What’s going on? Why is it not detecting your hand? Is it really your hand it wants? Some responses from students include: the electrons are not strong enough to get through your clothes; the shirt might have a positive charge and it repels anything trying to get to the phone screen; and even, electrons in my phone??

Chemistry, I remind my students, is part of your everyday lives … and one in which these negatively charged electrons play an important role. When you touch the screen, a tiny amount of energy is transferred from the glass screen on your phone to your fingertip. This transfer allows the phone’s computer to track the movement of your finger across the screen, and therefore, understand what you’re trying to make the phone do for you. Cell phone chemistry is fascinating, as shown in the 2015 ChemMatters article, Smartphones: Smart Chemistry. Yes, you can generate a charge!

Real-World Example 3: Human Conductor

Figure 2. An Energy Stick purchased from Flinn Scientific.

Here’s another activity that can help students understand how humans can be conductors of electricity. I show my class an Energy Stick (a great find from Flinn Scientific), and ask if anyone wants to hold the other end.

Kids typically do not jump up to help out with this demonstration. They’re wondering what’s going to happen. But eventually, I get a brave student to volunteer. Slowly, the entire class forms a circuit: the result is hysterical, of course, when it lights up and zaps! Discussions here are important. Let the students lead and try to figure out why this is happening. The short answer is that we are each human conductors — which they’re seeing firsthand. 

This leads me to an activity about pencil lead, everyday writing, and art, inspired by the 2007 ChemMatters article, What's That Stuff? Pencils and Pencil Lead (see Figure 3). In the activity, students compare how pencils write based on the markings on each one. How does this relate to conductivity? Graphite (pencil lead) conducts electricity. To demonstrate this fact, make a thick swatch of graphite on a piece of paper, and have your kids join hands. Have one student touch the metal end of the Energy Stick to the graphite, and it lights up!

Figure 3. In an activity about pencil lead, students use different pencils to compare the hardness and darkness of various formulations of graphite.

Real-World Example 4: Rust and Corrosion

In my opinion, student participation in memorable activities and labs is key to their understanding of abstract content. That’s why I feel that when students are learning about redox reactions, it warrants a lab experience.

Students are so familiar with these everyday reactions — especially that of rust. There are many relatable ideas, because rust occurs all around us: with personal possessions, bridges, cars, etc. The Corrosion of Iron Lab is my favorite strategy for concluding a unit about redox. If you plan to use it in your classroom, be sure to adhere to the proper lab safety precautions; the American Chemical Society provides a checklist for best practices. Students should also have gloves or tweezers available to safely handle rusty nails, and thus avoid the risk of tetanus infection.  

Students first complete a pre-lab that introduces them to how metals corrode and how to prevent it, followed by a discussion with their peers about the reactivity of metals. This prepares them for the lab, where they will intentionally corrode nails and also investigate ways to prevent corrosion. In their pre-lab discussion, they must discuss and justify predictions as to whether the iron will corrode; will it be protected using a sacrificial metal; and can we prevent it from happening?

Once setup is complete, students will investigate the results within a week, discuss whether their predictions were right or wrong, and try to determine why. We specifically discuss rust prevention methods to help students make real-world connections, such as which types of items can be safely left outdoors, the relation between a bridge’s age and its strength, and the corrosion experienced by boats in the ocean. We also discuss why nails are galvanized, and where these types of nails will be used. These examples are connected with two NGSS Disciplinary Core Ideas: PS1A: Structure and Properties of Matter and PS1B: Chemical Reactions.

Bring it home

Table 1 has a few additional suggestions, as well as some of my favorite ideas for connecting real-life examples to chemistry topics in the curriculum. Be sure that any labs used are designed with safety as the top priority. I encourage you to share your ideas with AACT so that we can all benefit from sharing these ideas. There are many more examples of chemistry in students’ everyday lives. I try to “bring it home” every chance I get, and I hope you’ll do the same.

References

Zumdhal, S. A.; Zumdhal, S. S. Chemistry, 8^th Edition; Brooks Cole: Belmont, CA, 2010.

Gonick, L.; Criddle, C. The Cartoon Guide to Chemistry; HarperCollins Publishers, Inc.: New York, 2005.

Photo credit:
(article cover) theseamuss/Bigstockphoto.com