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GLOBE Learning Experience 2018

Every 4 years, GLOBE hosts their annual conference outside the USA and this year we trekked to Killarney, Ireland to work with GLOBE coordinators, teachers, and students from all over the world. The conference began with an opening ceremony at the Killarney House which offered an incredibly scenic exhibit venue.

For the next several day’s attendees used PASCO equipment at two field sites to collect water quality data on the Owengarrif River. Sampling took place at the Upper Torc above the falls and the Lower Torc at the mouth of the river.

Having downloaded SPARKvue software to their phone or tablet the students and teachers connected to the Optical Dissolved Oxygen, Wireless pH, and Wireless Conductivity sensors to complete the Water Quality Protocol. We also deployed the new Wireless Weather Sensor which made the site set up a cinch, answering the two critical questions of “Where are we?” and “What are the current conditions?” right on the weather dashboard display.

While the map display is not required for this protocol being able to view the data in real-time on the map was helpful to give students a sense of the landscape and identify features that could impact the water quality. Happily, at every site, we sampled the Owengarrif was in good health, although it was running near-record low flow rates due to a 5wk drought and above-average temperatures.

Here’s a quick video of highlights during the conference – hopefully, we’ll see you there next year!

 

If you’re already a GLOBE teacher or PASCO user and want to see what protocols are supported with sensors, please visit our GLOBE page for an updated alignment. If you’d like to learn more about how to participate in the GLOBE program and get your students collecting data that will be used by scientists all over the world, please visit GLOBE.gov to get started.

Inquiry Learning Helps Keep Students in STEM

The use of technology in STEM education is quite important because it supports inquiry learning. With the newest innovations from science equipment companies such as PASCO, there are even more ways to support inquiry using hands-on learning. In several independent studies, using inquiry-based learning has improved student confidence, interest, and performance in physical sciences.

The Impact of Inquiry Learning for Science Students

One study in Thailand by Tanahoung, Chitaree, Soankwan, Manjula and Johnston (2009) compared two first year introductory physics classes at the same university. One class was taught using a traditional method while the other class used Interactive Lecture Demonstrations. Interactive Lecture Demonstrations is a form of inquiry; students first predict the outcome of an experiment individually and then in groups. The demonstration is performed in real-time using micro-computer based laboratory tools (in this case a PASCO interface and a temperature sensor) and then students and/or instructor reflect on the concept based on their predictions and the actual results. For each thermodynamics concept, a pre-lecture and a post-lecture test was administered for comparison.

Tanahoung et al. found that in almost all of the concepts, there was a greater increased of percentage of correct answers between tests from the experimental group than the control group. These results show that teaching methods that use inquiry and technology are a novel and viable pedagogy for the 21st century.

Inquiry-based learning has been shown to improve grades in physical science courses for non-STEM students. In one particular study by Hemraj-Benny and Beckford (2014), a chemistry concepts such as light and matter was taught in relation to visual arts using a combination of traditional lectures and inquiry activities. The experimental group participated in group discussions, performed experiments using worksheets, created presentations, and had a summary lecture from the instructor. In contrast, the control group only had lecture-style lessons in which the instructor went over PowerPoint slides and certain scientific experiments in detail.

As a result, the class that received both inquiry and traditional lessons performed better in their final exam than the control group. More students in the experimental group reported better confidence and less fear in science than the control. Interestingly, Heraj and Beckford found that both the control and experimental group reported to have a greater appreciation of the scientific world after completing this course. Overall, this experiment shows that inquiry methods are especially beneficial for non-STEM students in understanding physical sciences. The critical skills taught in this course is an excellent example of how STEM skills can benefit everyone, including non-STEM majors.

The use of personal multifunctional chemical analysis systems has greatly improved student perception on chemistry experiments. As reported by Vanatta, Richard-Babb, and Solomon (2010), West Virgina University switched to the PASCO SPARK learning system and reported several benefits to using such systems like “less ‘waiting around time’” (Vannatta, Richard-Babb & Solomon, 2010, p. 772), the possibility of interdisciplinary and field experiments due to the versatility of using such equipment. Such as portability, ease of use and using microcomputer-based laboratories allows students to move at their own pace instead of waiting for others to move on. All of these benefits are factors to increased student retention and interest in chemistry majors.

Additionally, PASCO has upgraded from the portable SPARK learning system with built-in software to the downloadable SPARKvue software for computers and mobile devices. In another study, Priest, Pyke, and Williamson (2014) compare student perception using a handheld datalogger (the PASCO GLX system) versus SPARKvue on a laptop for the same chemistry experiment. Students were surveyed after using the GLX system for a vapour pressure experiment on their opinion on the lab. The next year, the school had phased out the GLX system and introduced SPARKvue using a laptop interface but kept the lab exactly the same. Researchers noticed more positive responses to the experiment when students used the laptop interface. Students perceived that the experiment was simpler and that the content was easier to understand when using SPARKvue because students are more familiar with a laptop and not a traditional datalogger, they experienced less frustration and spent less time learning how to use the necessary software to gather data.

A Guided Inquiry Lab – Results May Vary!

In my own studies, I benefited from inquiry labs and technology definitely made these labs easier. One of my favourite labs was a dart gun experiment where our groups were challenged to determine the theoretical spring constant of a dollar store dart gun by devising our own method. The goal of the experiment wasn’t to determine the actual spring constant since there weren’t actual springs in the dart gun, but to use what we knew from other units to create an experiment. We were given free reign over all the equipment in the classroom including the PASCO GLX and motion sensor and needed to keep a lab notebook in order to note any changes to the experimental method.

My partner and I opted for a low-tech option (pictured right) – we weighed the dart and determined the maximum height of its flight upwards so we could plug it into a kinematics equation to find the vertical velocity of the dart when it exited the chamber. This method was sort of tedious – I would launch the dart from the floor while my friend would video the dart on her phone while standing on a chair so we could replay and record when it reaches maximum height. This resulted in a few mishaps such as the dart perfectly falling into the adjacent broken glass box which we promptly moved. We also had to make several modifications to our experiment design to ensure that our data collection was consistent such as taping the dart gun so it exits perpendicular to the ground and adding weight to the dart gun so it doesn’t hit the ceiling before it reached its maximum height.

Another group decided on the easier (and safer) option of using the GLX and motion sensor to capture the horizontal acceleration of the dart when launched off of the table to model a Type 1 Projectile Motion problem. This method reduced a lot of uncertainty in their calculations since the sensors could accurately capture their data and they had the added benefit of not needing to precariously stand on a chair and guess-timate the maximum height. They also managed to finish a lot earlier and have more experimental runs than we did.

Although the sensors did end up making the experiment a lot easier for them, both of our groups were able to make connections between units and truly use the scientific method which made the experiment so much more interesting than our usual structured inquiry labs.

How You Can Support Inquiry Learning in Your Classroom

From these studies it is clear that inquiry-based learning and technology in STEM classrooms have short-term benefits such as increasing student interest and confidence. In addition, these two approaches to learning are complimentary to each other. The ease of use from technology decreases wait times and allows students to move at their own pace. Because students can move at their own pace, they are able to ask questions about the experiment itself. Students are able to benefit from making mistakes in this environment because the data logging software allows them to analyze what they did incorrect and why it is happening.

Through this approach, students are able to be curious in a controlled environment whilst developing essential scientific inquiry skills. There is also more time for meaningful discussion during class through using probeware since it reduces the amount of set up and lessons on how to use the equipment. Because of this, students are less likely to get frustrated or bored from experiments and helps students understand or reinforce their knowledge in the subject. This could improve the number of students pursuing a science education since students are less likely to leave if they are interested and confident in what they are learning.

PASCO and AYVA have a significant amount of resources that further demonstrates the positive impact that probeware technology has in science education such as White Papers on how PASCO supports scientific inquiry. AYVA also provides Curriculum Correlations for Canadian provinces which provides suggestions on how to incorporate PASCO technology into science classrooms across Canada.

 

References

Hemraj-Benny, T., & Beckford, I. (2014). Cooperative and Inquiry-Based Learning Utilizing Art-Related Topics: Teaching Chemistry to Community College Nonscience Majors. Journal of Chemical Education, 91, p. 1618-1622

Priest, S.J., Pyke, S.M., & Williamson, N.M. (2014). Student Perceptions of Chemistry Experiments with Different Technological Interfaces: A Comparative Study. Journal of Chemical Education, 91, p.1787-1795.

Tanahoung, C., Chitaree, R., Soankwan, C., Sharma, M.D., & Johnston, I.D., (2009). The effect of Interactive Lecture Demonstrations on students’ understanding of heat and temperature: a study from Thailand. Research in Science & Technological Education, 27(1), p. 61-74.

Vannatta, M.W., Richards-Babb, M., & Solomon, S.D. (2010). Personal Multifunctional Chemical Analysis Systems for Undergraduate Chemistry Laboratory Curricula. Joural of Chemical Education, 87(8), p. 770-772.

Having the Right Attitude Towards STEM

In my high school years I found that many of my classmates hesitated in pursuing science and engineering because of the ‘M’ in STEM. Math. When I was younger I didn’t really understand why everybody hated math so much – in my opinion it was more fun than having to draw (I’m a pretty bad artist). It also helps that I had a good teacher in grade 5 and 6 that gave me a healthy respect for math. Her math tests were infamous for being long and difficult but it helped me develop the necessary skills to succeed in high school.

I find that the biggest issue for students is that they have a negative view towards studying STEM and it’s a result of years of conditioning from teachers, parents, and peers telling them that the content is difficult to learn. Although it is not intentional, it has a significant effect on a student when they start thinking about what career they want to pursue.

EEK IT’S A PARABOLA! Oh wait it’s just a ghost.

Although Math is its own discipline in STEM, all the other disciplines (science, technology, and engineering) inevitably involves math in some way. So many students have a fear of math and will avoid certain disciplines because it requires math. Quite often I would hear my classmates say that they won’t apply to a specific post-secondary program because it requires grade 12 calculus. This fear of math is so prevalent in our culture that it is almost like a badge of honour to say that you’re “not a math person”. My first year calculus professor has a good blog posts (here and here) that outlines why math anxiety can be detrimental and has other math resources and activities for teachers.

This applies for teachers as well – showing fear of math or any other subject can greatly affect how a student perceives that subject. In order to address this problem, STEM education for pre-service teachers must be improved. In one study by Gado, Ferguson, and van’t Hooft (2006), pre-service chemistry teachers were taught using probeware in their experiments which resulted in greater confidence in these subjects. By having more confidence in teaching the content, the teachers are less likely to project a fear of STEM but instead an interest and enthusiasm for the subject.

Using mathematical concepts in science is an effective way to make math seem less like a scary ghost. There are many ways to help your students reinforce their math skills within science lessons. With the use of probeware with built-in graphing software, math can be readily applied to real-life concepts thus helping students understand concepts both numerically and visually. It also explains math in a different way that some students may find more understandable.

Failure Is Not An Option (Or Is It?)

I think this negative attitude towards math and difficult subjects in general comes from the fear of failure. Acceptance into post-secondary education heavily relies on what grades students have and having a low score in a course could influence whether or not they get into a certain university program. I admit that I didn’t want to take physics or calculus because I knew that it would lower my acceptance average since they were quite difficult subjects.

What I learned from these courses was far more valuable to me than a few percentage points and I’m not talking about derivatives and quantum physics. I learned how to fail in physics and calculus. I did have a fear of failure – the thought of even getting a 70 in a course was terrifying for me until grade 11. Learning new things was always easy for me and failure was never an option for the overachieving 16 year old me.

I failed a test in high school for the first time in my grade 11 physics class which was absolutely devastating. After some tears I picked myself up and tried to figure out where I went wrong. Obviously my study skills at the time weren’t effective so I had to develop different skills that would suit this type of course. I learned from my mistakes and tried harder. I ended up finishing that class with a 90 and an important life lesson. I learned that failing is okay as long as you learn from your failures. This is something that I didn’t really understand until I actually experienced it.

Although something is considered difficult or you think that you might not be good at it, it shouldn’t prevent you from at least trying. There is always something to learn from failure, even if it’s simply the confirmation that something is definitely not suited for you. This applies not only to STEM but in life.

In order for more students to pursue a STEM education, we need to start encouraging students to get out of their comfort zone and challenge themselves in areas that they are not as strong in even if they may fail. Remember, failure is an option!

References:

Gado, I., Ferguson, R., & van’t Hooft, M. (2006). Using handheld-computers and probeware in a Science Methods course: preservice teachers’ attitudes and self-efficacy. Journal of Technology and Teacher Education, 14(3), p. 501+.

Stoked About Stoich

Stoichiometry – No Limits to Limiting Reactants

If there’s one thing virtually all chemistry teachers can agree on, it’s that stoichiometry is a difficult topic for students. A problem can involve writing chemical formulas, balancing equations, then multistep calculations converting amounts from grams to moles and back again. Just writing those sentences helps me understand why students struggle! On top of all of this, we also ask our students to identify limiting reactants and determine percent yield for an experiment.

There are a number of tools and methods teachers employ to get students through this tough topic, including flow charts, algorithms, the Before Change After (BCA) approach, and physical models to reach students. We even use analogies of bikes, cookies or hamburgers to make limiting reactants relatable.

Hands-on inquiry can be another practical and tangible tool. A simple experiment using household chemicals, a bottle (or flask) with a stopper and tubing, and a Wireless Pressure Sensor can give students the opportunity to easily change the amount of one reactant while quickly measuring the amount of product to see the limits of the limiting reactant.

In this experiment from our Essential Chemistry Laboratory Investigations book, students perform multiple trials, keeping the amount of baking soda (sodium bicarbonate – NaHCO3) constant while increasing the amount of citric acid (C6H8O7). To keep the procedure simple, dissolve sodium bicarbonate in water to make a 0.12 M solution. Don’t worry if you haven’t covered molarity yet – let the students know that for 1000 mL of solution, there are 10.24 g of NaHCO3. Then, when they use 40 mL of sodium bicarbonate solution for each trial, they can practice proportional reasoning to determine that there are 0.41 grams of sodium bicarbonate are in each sample.

They should mass 0.10 grams of citric acid after they add 40mL of NaHCO3 solution to the reaction vessel. After connecting the Wireless Pressure Sensor to SPARKvue and opening lab 8D in the Essential Chemistry folder, students can start data collection. Once they establish a baseline pressure they should add the citric acid and quickly stopper the bottle. Make sure one student in the group is firmly holding the stopper in place while swirling the bottle during data collection.

Once the reaction is complete, it’s time to analyze the data!

The change in pressure is based on the gas produced during the reaction.

Next, it’s time to repeat the experiment, but with 0.20 g of citric acid. If you ask the students to predict what will happen to the pressure most will (correctly) assume that the change in pressure will double since they have twice as much reactant. They can do the same with 0.30 g of citric acid.

Something funny starts to happen when 0.40 g of sodium bicarbonate is added. The change in pressure is not four times the 0.1 g sample. And when 0.50 grams of sodium bicarbonate is added, it is the same change as 0.40 g. How can this be?

They can graphically analyze this discrepant event this by plotting the change in pressure vs the mass of sodium bicarbonate and viewing all of 5 of the data runs.

Some students will realize that the later trials did not produce proportionally higher changes in pressure because there was not enough sodium bicarbonate to react with all of the citric acid. This is a great observation and the key to understanding limiting reactants. They have made the connection that something will run out and stop the reaction!

Based on the graphs, the third trial is closest to an ideal ratio of reactants. In trials 4 and 5, there is not a proportional increase indicating that some of the citric acid did not react. To explain this, they need to dig deeper into the data and convert masses of reactants into moles.

Looking at the third trial, they have 0.41 grams of sodium bicarbonate, and 0.30 grams of citric acid. Using the molar masses of NaHCO3 and C6H8O7, they can calculate that there are 0.0049 moles and 0.0016 moles respectively. This is a 3:1 ratio.

To put all the pieces together, one more bit of information is needed– the balanced equation!

3NaHCO3(aq) + C6H8O7(s) → Na3C6H55O7(aq) + 3H2O(l) + 3CO2(g)

There’s the reason for the 3:1 ratio of moles of sodium bicarbonate and citric acid! Anytime the reaction has something other than a 3:1 ratio of the reactants, one of the reactants limits the production of gas. Now they can then look at each of the trials, identify which reactant is limiting, and provide evidence to support their claim!

This simple experiment with household chemicals gives students the experience and data to understand the limits of a limiting reactant, how the limiting reactant can change based on the amounts of substances, and why simply adding more of a reactant does not always lead to more product. Armed with these understandings, there will be no limit to their success!

The Cost of a STEM Education

Another major factor is simply the cost of a science and technology education – you can’t learn computer science without a working computer!

Technology has shaped education and how students learn – many teachers are opting to use online assignment submission, encouraging students to download lessons from a school website, and communicating to their students via Twitter. I still remember going to the computer lab with my class to play Math Circus, a series of circus mini-games geared to teach children math.

There are also so many free resources available for educators that can supplement their lessons and help students. Many of these resources are available through an app on a mobile platforms but what about schools and communities that don’t have the funds to access such technology?

Some schools have a Bring Your Own Device program to save the cost of buying a class set of tablets or laptops. Some schools discourage this program because it is not guaranteed that all students will have a device so they will purchase their own technology.

Technology Supports Inquiry Learning:

Whilst technology may have been a ‘want’ ten years ago, now it is a ‘need’ for educators as more provinces and school boards make 21st Century learning skills and inquiry skills a requirement for classrooms.

Inquiry-based learning is a pedagogy that is focused on learning using constructivism, which involves an individual’s participation to facilitate their own learning. In other words, a student must be engaged, actively thinking, asking questions, making connections between their knowledge and real-life examples, and use hands-on activities to concretize their theoretical knowledge (Minner, Levy, and Century, 2010, p. 476-476). In fact, inquiry-based learning has been shown to improve grades in physical science courses for non-STEM students (Hemraj-Benny and Beckford, 2014).

Inquiry learning is a fundamental aspect of science education since the nature of the subject is to ask questions and use what you know to develop a way to answer your question.

Even if a school can afford computer carts or tablets, there are recurring costs in a science department.  In a science department equipment such as glassware, reagents, and rats for dissection must be replenished every year in order to do experiments.

Experiments support a student’s inquiry skills which are important for a budding scientist but with the high cost associated with science experiments, how can students learn?

As previously mentioned in another blog, I struggled to understand physics so I only fully grasped it when I did the experiments. I was lucky to have a teacher that did an experiment at the end of every unit and to be in a well-equipped physics classroom with an air track, metal carts, optics equipment, and PASCO sensors. I cannot imagine passing my high school physics classes if I didn’t have the resources available.

What Can We Do?

There are many government funded outreach programs that bring science experiments to your classroom for free. Quite often, university students volunteer to visit the classroom for a workshop and they will bring all the necessary equipment to perform an experiment.

In my school we frequently had visitors for McMaster science and engineering outreach programs to do a specific experiment for that day. During one of these visits, each group of students were able to build their own circuit and create a solar car that we later tested outside.

There are many programs like this all around Canada and a lot of them are affiliated with a post-secondary institution so it can double as a career-planning workshop for your students. One of the biggest outreach programs and an incredible resource for science educators in Canada is Let’s Talk Science. Let’s Talk Science conveniently provides a page dedicated to finding a local outreach:

In terms of technology, there are a lot of grants available from some of the biggest companies in Canada such as the Best Buy School Tech Grant which also has a specific STEM school category and the Staples Superpower Your School Contest for environmentally conscious schools. Check out our AYVA grant page to see what’s available!

 

References:

Hemraj-Benny, T., & Beckford, I. (2014). Cooperative and Inquiry-Based Learning Utilizing Art-Related Topics: Teaching Chemistry to Community College Nonscience Majors. Journal of Chemical Education, 91, p. 1618-1622

Minner, D.D., Levy, A.J., & Century, J. (2010). Inquiry-based science instruction—what is it and does it matter? Results from a research synthesis years 1984 to 2002. Jouurnal of Research in Science Teaching, 47(4), p.474-496.

What Prevents Students from Pursuing STEM (And Why I Pursued It Anyway)

Article after article highlights the lack of diversity in STEM – not enough women, not enough racial minorities, not enough people from lower socioeconomic classes. There are also articles that dispute that the STEM gender gap doesn’t exist and that there are equally as many female STEM graduates as their male counterparts (that will be covered in a future blog).

Numbers aside, today I will be covering a few reasons why students don’t feel that a STEM career is an option for them and how I pursued one despite these reasons.

Some of the commonly cited reasons for students avoiding STEM are the lack of role models in these fields, peer pressure, and overall perception of STEM.

So why do people avoid STEM?

Students typically dismiss science educations because they do not see many role models that they identify with in this field. They feel that they would not fit in or underestimate their skills to pursue such a degree.

In a study by Microsoft, it was determined that having effective role models and support from parents and mentors are needed for females to see themselves in a STEM role. Exposure to STEM activities and real-world applications also influenced how females perceive STEM jobs and their class choices later in their life.

Although this study focused on women in STEM, these environmental factors can also influence students of different ethnicities, orientations, and abilities. Everybody has a different identity – it is important to realize that not one person fits into one single group. But the approach to encourage more students to pursue a science education is the same: good role models, a support system from educators and family, and exposure to science in different contexts.

Why I Still Ended Up in STEM

Although I had decided that I wanted to study science in high school, I nearly didn’t go into chemistry. My high school had a large proportion of students taking at least one senior science and many graduates pursued post-secondary educations in STEM. Science was something that all of my peers were doing and it was something that I excelled in so I decided to take all three courses offered (biology, physics, chemistry).

I loved my chemistry class – I did extremely well and it was so interesting to me. However, I was considering biology as a major because I didn’t excel in grade 11 physics and a chemistry major relied heavily on some physics concepts. Half of my friends were going into biology or healthcare but I couldn’t find a biology major that I was really interested in and I definitely did not want to go into nursing. At the time I was worried about risking my university acceptance average by taking such a difficult subject like grade 12 physics.

I reluctantly took grade 12 physics after consulting with my physics teacher even though I could get into my desired chemistry programs without it. Only a few of my friends were taking physics and I felt like everybody in my class smarter than me. The majority of my classmates were going into either engineering, computer science or pure physics.

I had many people in my life that encouraged me to pursue a chemistry degree but it was my physics teacher that helped solidify my choice.

My high school physics teacher was female and she was one of the best teachers in the school. To see a woman teach one of the hardest courses in the curriculum was quite encouraging for me especially since I doubted my abilities amongst my predominantly male pre-engineering peers.

She always tried to do what was best for her students which included telling us some hard truths. Her class also humbled me – I learned how to fail in her class and come out better. Even though I didn’t do as well in her class compared to my other courses, I finished that course feeling like I earned the mark.

Because of her support, I was able to picture myself studying chemistry and to not fear physics. She was always open to providing extra help and giving honest advice on university program choices.

I also had amazing support from my female peers in that class – the class went from 25 students at the beginning of the semester to about 7 by the end of the semester. Half of the students left in our little group were female including me and the entire class became more of a study group than an actual class. The small class size and the fact that I was not the only girl in the room helped me persevere through grade 12 physics. All of the females in that class ended up pursuing degrees in the physical sciences or engineering.

That is just one example of how being taught by somebody and being surrounded by peers that I identify with empowered me to study chemistry. This is why support, role models, and outreach programs are vital for encouraging more underrepresented groups to choose STEM careers.

Despite this, there are still other major reasons other than underrepresentation as to why Canada doesn’t have enough STEM graduates which will all be covered in next week’s blog!

A Student’s Perspective on STEM Education: A Blog Series

Throughout the summer, AYVA will be launching a blog series all about the use of technology in STEM education.

My name is Katrina and I started at AYVA in January as a co-op student from the University of Guelph. I am a Biological and Pharmaceutical Chemistry major and STEM education has always been something that I am passionate about. I feel like I am in a unique position to help improve it through AYVA as a student who has recently experienced secondary science education and is currently studying science in university. I have some perspective on how technology can be used to improve learning having used PASCO technology both in high school and university.

Through this series, I will be covering some successes, issues, and perspectives on the status of STEM education in Canada along with my personal experiences as a STEM student in Canada.

Why does this series matter?

I am one example of how good teaching can truly inspire a student to pursue science and can make a significant impact on their educational choices and career path.

I was very fortunate to go to a high school in the Dufferin-Peel Catholic School Board that had an incredible science department. In that department, I have had various role models and mentors who helped me realize what I wanted to do.

Through these teachers, I have had so many opportunities to confidently pursue science. They helped me attend STEM outreach camps, provided extra help and resources, let me into their classroom after class hours to talk about advanced topics and issues in science.

My high school mentor helped my friend and me to pursue a graduate-level research project at the University of Guelph while we were still in grade 12 for a competition. How many people could say that they did that at 17? I owe a lot to my teachers for helping me achieve my goals and for guiding me to where I am today.

I also attended a high school that was relatively new and as such had many resources available for inquiry learning. We had SmartBoards, laptop carts, and PASCO equipment for our science department. This technology helped supplement my lessons and made me understand some more difficult concepts. The PASCO equipment in particular helped me quite a bit in my physics classes – it was the only class where I never fully grasped concepts until I did the experiments.

With that being said, I know that not everybody has access to a good science education. I know that I am fortunate to have gone to a school with teachers that have the resources to ensure that their students succeed. This is why I am writing this series – I want to highlight some of the key issues in STEM education and give insight using my own experiences. Through this, I hope that I can inspire others to push for better and accessible STEM education.

And The Award Goes to Rory Armstrong

Pictured above: AYVA’s C.O.O. Brad Beveridge with Rory Armstrong at Huron Parks graduation ceremony.

Each year AYVA invites submissions from middle school students who have assumed leadership roles both at school and in the community.

We continue to be impressed by the caliber and commitment of those students who strive to make a difference.

This year’s winner was from Huron Park School in Midland, Ontario.

Congratulations Rory Armstrong, you are a role model indeed!

Titrations are pHun

Properties of acids, bases and the pH scale are core concepts in any chemistry class. After your students understand the basics, they need to be able to quantify reactions involving acids and bases with a titration.

A classic experiment is to determine the concentration of HCl(aq) by reacting it with 0.1 M NaOH(aq). To quantify this titration, and to make it more pHun, I used an indicator and a Wireless pH Sensor.

The volume of labware usually used for a titration can cause students to react with hesitation about the lab, so to keep the focus on the concepts, I minimize the amount of equipment. For a mini-titration station, I lighten the cognitive load by having students measure volumes in drops— no funnels, burets or volumetric glassware needed.

In the setup above, I added 60 drops (~2 mL) of an unknown concentration of acid to a beaker on a magnetic stirrer. Then I used the Electrode Support to suspend a Wireless pH Sensor in the beaker with enough water to make sure the pH electrode is covered. Finally, I added a few drops of bromthymol blue indicator. I fired up SPARKvue and set up a table to manually collect pH measurements and the volume of NaOH.

Now, it was time to drop the bass base. I slowly added 0.1 M NaOH until the pH changed by 0.5 units (up to 13.0 units), recording the total drops of NaOH along the way.

After only a few minutes, your student will have a constructed a pH titration curve with real measurements with no treble trouble. This data looks good to the last drop!

Students will be surprised at a couple of things. The number of drops needed to change the pH by 0.5 units is not always the same, and the shape of the titration curve is not a straight line, as many would have predicted.

They will also have noticed that the indicator in the solution changed color, from yellow to blue, and there was a big jump in the pH with only 1 drop of NaOH.

So, what’s the point of all this data? In this case, there is an exact point they are looking for— the equivalence point.

When the 60 drops of HCl were neutralized by 52 drops of 0.1 M NaOH — indicated by the color change and large jump in pH from below 7 to above 7— there were an equal number of moles of acid and base in the solution.

By incorporating the Wireless pH Sensor the students will not only perform a color-changing titration, but they will also have an opportunity to engage in some science and engineering practices with their data. And of course, have some pHun doing it!

Water Purification

Water is a precious resource, but not all water is potable and ready for consumption. Since water is a “the universal solvent,” it can dissolve many substances. Luckily, the physical and chemical properties of water and the solutes allow for purification if the water has been polluted. One method of water purification that students can model and re-engineer in the lab uses distillation and condensation.

For this activity you can collect a sample of water from any local source – a stream, creek or pond. Don’t go chasing waterfalls because you could also prepare you own sample. This blue “dirty” water sample was made right here at PASCO with some tap water, salt, starch and food coloring to make the changes more visual.

The first step is to make observations and measurements of the original sample. The blue color was obvious, but we also need to use sensors to measure the any unseen solutes.

First up, we can use the Wireless Conductivity Sensor to keep an eye on the ions by measuring any dissolved ionic solutes.

The conductivity reading is 17562 mS/cm. It isn’t apparent by looking at it, but the sensor makes it clear – there is a significant concentration of salts in the sample.

There’s no smoke in the water, but you can tell by looking closely that it is a little cloudy. The measure of cloudiness is called turbidity. We can use the Wireless Colorimeter and Turbidity Sensor to quantify the cloudiness.

The turbidity measures 111.7 NTUs. The data is clear, the water is cloudy. Based on the original observations and data, the water is blue, it has some dissolved ionic solutes, it also has some larger dissolved particles creating a suspension.  Â

Now for the fun part. It is time to purify the sample!

Some of the sample is poured into a small beaker and put on a hot plate and turned to the highest setting. In the image below, what you see isn’t a bridge over troubled water – it’s the new PASCO Condenser. The Condenser, with ice, is positioned over the beaker. As the “dirty” water boils, steam evaporates. The steam then hits the underside of the cold Condenser top and condenses from the gaseous state back into a liquid. Once in liquid form it collects in the black bottom of the Condenser.

Let it boil for 15 minutes and you should collect about 10 mL of “clean” water. Then pour into a test tube to compare to the original.

It definitely looks purer because we can now see it’s a clear, colorless liquid. But we need to collect more evidence to see if the purification was successful.

The data indicates that the water is clean as it looks! Both the conductivity and the turbidity measurements are now close to zero.

With this activity your students can gain some practical experience with a purification technique. The sensors provide them with clear evidence of the effectiveness of the process. The next step is to challenge your students to design and build their purification system!

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