Post-Secondary – Page 4 – AYVA Educational Solutions

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.

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 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!

Going Wireless: Shifting Augustana’s First-years Labs

Written by: David King, University of Alberta – Augustana Campus

The Augustana Campus chemistry labs have traditionally been perfectly acceptable, but have yielded somewhat standard chemistry experiments with very typical analysis. As a satellite campus of the University of Alberta, located in Camrose, Alberta, we have strived to be almost an extension of our North Campus sibling, which has proved problematic within the constraints of a 100 kilometers distance. Recently, things have changed. Last summer, we diverged from this straightforward and customary path and decided to do something slightly different. Along with our newly renovated labs—that encourage thought and collaboration—we have fundamentally changed our first-year chemistry lab experiments, which mean that different analyzation techniques are needed. Gone are vitamin C titrations with Tang and tablets, replaced by extraction techniques and spectral analysis. Hand-held spectroscopes have been replaced with a fiber optic cable in a light emissions lab while also adding a light measurement for chemiluminescence.

Our previous vitamin C laboratory experiment was based in a traditional vein, where titrations were used to determine the vitamin C content in both Tang (a powdered orange drink very few students today have ever experienced) and 500mg vitamin C tablets. Being a “traditional” lab exercise meant that most students likely had seen this done in high school or had done this very titration themselves. Our goal was to create an experience where the students learn a new analytical technique by extracting vitamin C from a pepper, then determining the vitamin C concentration from a standard calibration curve on a PASCO Wireless Spectrometer. All of these skills are taught in the first week of this exercise. Week two is all about the inquisitive nature and enthusiasm of the first-year chemistry students. We wanted them to start critically thinking about what they read and whether or not it is scientifically sound, and we also wanted students to gain confidence in their research abilities right away, both in a laboratory setting and with data analysis. The idea is that students would formulate a research question and then create a hypothesis to test in the lab to add to their skills. Since the PASCO Wireless Spectrometers allow us to keep data sets, we could use the same calibration curves throughout the testing.

Student Myths Tested:

Different cooking methods affect on Vitamin C
Different storage methods affect on Vitamin C
Freshly squeezed vs. prepackaged juice
Over the counter vitamin C supplements vs. natural sources
Comparing vitamin C content of fruits and vegetables from different international origins

Light emissions lab experiments can be tedious at best. You need to constantly be looking through a hand-held spectroscope, which is exactly what we were asking our students to do. Also, we were looking at lights, flame tests and emission tubes with said spectroscopes. Throughout all of this, we weren’t asking the students to really do anything else, chemically speaking. Chemiluminescence and chromatography columns were two things we decided to add into our updated labs, along with the fiber optic cable accessory for the Wireless Spectrometers (as well as scaling back the spectroscope use). In the first part of our experiment, students would activate a glow stick and add the content to our 3D printed Light Calorimeter, then read the light emitted using the PASCO Wireless Light Sensor. From here, students would take the glow stick content and run it through a silica gel column to remove the chemical that activates the “glow”, then read the light emitted again. Peroxide and sodium salicylate would then be added to get the “glow” to return, and one last reading on SPARKvue would be taken.

By using this method, we wanted students to learn not only about columns and their ability to separate mixtures but also to get comfortable learning how to collect data using a sensor and a data logger (in this case an iPad). In the second part of our experiment, we still use traditional light emission tubes (Argon, Helium, etc.) where we use spectroscopes to obtain the emission spectrum lines. For the hydrogen tube, however, we set up the fiber optic cable accessory and the PASCO Wireless Spectrometer to get the most precise emission light spectrum we can. Ideally, the students learn both techniques but come away with the appreciation for the newer tech.

Changing these two experiments to incorporate PASCO equipment and using different techniques has allowed the students to get a more modern feel for newer types of equipment and techniques that are more advanced than your “standard chemistry type” experiments.

Since the wireless sensors are easily incorporated into our lab designs, we have set our sights on adding the brand new PASCO Wireless Colorimeter to our forensic based Escape Box Lab to give students an idea how an analysis of this type could be performed in the field.

We also have a unique laboratory based three-week course for non-science majors that utilizes the PASCO Wireless CO₂ sensor in an interesting way. Our laboratory future is both bright and innovative, and more importantly, possible, with the tools from PASCO at our disposal.

PASCO products mentioned in this article:

AYVA Travels to PASCO for Global Partners Meeting

Six members of the AYVA Team spent last week in Roseville, California at PASCO Scientific’s headquarters.

We were excited to make new acquaintances and to reconnect with our friends from years gone by.

Representatives from more than 40 different countries had an opportunity to share success stories and receive training on PASCO’s latest products and new learning management software.

We even got a sneak peek at PASCO’s Roadmap for future development initiatives. A big shout out and thank you to our very gracious hosts at PASCO.

Measuring Headwinds and GPS Speed with PASCO’s New Wirelsss Weather Sensor

PASCO’s new wireless weather & environmental sensor with GPS provides for some obvious investigations such as monitoring changes in weather. However, as this sensor measures 17 different parameters, there are almost countless ways that measurements can be used individually or in combination to explore the world.

Two of the weather sensor’s 17 measurements relate to speed – the wind speed and movement speed of the sensor itself (as provided by the GPS sensor). Recognizing the similarity of these two measurements I was curious if the weather sensor’s GPS could be used to assess the accuracy of the weather sensor’s wind speed measurement.

GPS speed has proven to be very accurate, especially in open spaces, where there are no trees or buildings blocking satellite signals. Therefore, using the GPS to evaluate the accuracy of the wind speed sensor is a reasonable test.

Without over thinking the experimental test, I decided to go for a quick run across our parking lot holding the sensor up in the air like a torch carrier in the Olympics (okay maybe I’m over-romanticizing) and see how the headwind I generate from my sprint correlates to the GPS Speed measurement.

Being in less than optimum shape, after a long winter hiatus from anything resembling exercise, I kept my run to about 100 M (50 M in both directions). Looking at the satellite image below that depicts my run (each dot is a separate measurement), you’ll see that there were cars in my way requiring several strenuous leaps.

Notwithstanding the strange looks I received during my run, the test proved quite successful. The graph below shows wind speed in green and GPS Speed in blue. During the first half of the run the two speeds correlate very closely. On my return however there is a significant difference which I suspect was caused by a trailing wind gust that would have the effect of reducing the headwind.

In conclusion it appears that the Weather Sensor measures wind speed fairly accurately. However, in this test the wind speed sensor is measuring headwind which is a combination of traveling speed and actual wind. Therefore more rigorous testing would be required to make a fair assessment, with external sources of wind eliminated or at least accounted for (can you think of ways how this might be done?).

In the classroom I suspect the weather sensor will be used in many interesting ways that has little to do with weather. In the months to follow I hope to share some more of my playful discoveries with this sensor.

“Like Dissolves Like,” But How Much?

After introducing the concept of “like dissolves like,” sensors can be used to quantify how much solute is dissolved in a solution.

Conductivity is a great tool for quantifying the amount of particular types of solute in a solution. Depending on the type of solute, students can “conduct” an experiment that makes them concentrate on concentration.

There is a linear relationship between the concentration of an electrolyte and its conductivity.

In this activity, based on a lab in Essential Chemistry, the relationship between concentration and conductivity is explored and data is collected with the Wireless Conductivity sensor. The first set of data represents a solution with increasing amounts of salt added. Since salt is an electrolyte, the conductivity is linearly related to the concentration. The second set of data represents a sugar solution. Sugar is soluble in water but, as a non-electrolyte, the concentration cannot be related to the conductivity measurement.

Sugar may be sweet, but the conductivity data of sugar solutions is definitely not. Luckily, sugar molecules have a chiral center and are optically active. The amount of optical rotation will depend on the type and amount of sugar present. Using a Wireless Polarimeter, you can measure the optical rotation of a variety of sugar solution concentrations.

The Polarimeter measures the light intensity vs the angle of rotation.

The change in optical rotation is linearly related to the concentration of the sugar solution.

Determining the amount of solute in a solution is an important part of any chemistry class. Having the appropriate sensors, and knowing the properties of the solutes and solvents, gives students the tools they need to quantify the concentration of a solution.

Glow in the Dark Science!

Fall is in full swing and Halloween is approaching. It’s the time of year for glowing ghosts, ghouls, and… science experiments!

Things that appear to glow are luminescent. Luminescent materials are literally “cool” because they give off light without needing or producing heat. Luminescence can be broken down into the following main categories: fluorescence, phosphorescence, and chemiluminescence.

Fluorescent materials will absorb energy, then quickly re-emit the energy. As a result, they only appear to “fluoresce” when they are in the presence of some form of radiation such as ultraviolet light.

The PASCO Spectrometer allows you and your students to experiment with fluorescence. Fluorescein, as the name implies, is a chemical that will exhibit fluorescence. In this demonstration, a small sample of fluorescein is diluted in water, then added to a cuvette. When held under a blacklight (ultraviolet radiation source) the sample will glow. In the Spectrometry App under Fluorescence, we can set an excitation wavelength to 405 nm.

Spectrum of the 405 nm light used for fluorescence excitation.

When the cuvette with fluorescein is added to the Spectrometer, you can observe the “glow” indicating fluorescence.

Fluorescein “glowing” in the PASCO Spectrometer.

Now we can observe the spectrum of the emitted light when fluorescein is excited with 405 nm light.

The spectrum of fluorescein

By overlaying the spectra, we can compare the wavelength of the light that went into the sample and the light that was fluoresced by the sample.

Notice the shift to a higher wavelength from excitation to emission.

Phosphorescent materials glow in the dark. Similar to fluorescence, they get excited by white or ultraviolet lights. But these materials slowly re-emit the energy in the form of light, even when the lights are turned off. Glow-in-the-dark toys are a great example of phosphorescence.

Finally, chemiluminescence occurs when a chemical reaction produces light without producing heat. Glow sticks are a perfect Halloween example of this. When the chemicals are mixed, a ghostly glow is given off.

So, the next time you see a glowing jack-o-lantern or an eerie zombie, don’t just think scary… think science.

Ready to Ship Advanced Physics Teaching Apparatus

It’s hard to believe that the end of the budget year is fast approaching. If your department has unspent funds now is a great time to consider acquiring one or more of PASCO’s premier instructional apparatus. The very popular featured products below are all in stock and can be shipped in time to make this year’s budget deadline.

1. Microwave Optics

The transmitter emits a large 3 cm wavelength that makes it easy for students to visualize and understand electromagnetic interactions. The system can be quickly adjusted with magnetic mounting components, rotatable transmitters and receivers and a Goniometer with rotatable arms featuring built-in degree and millimeter scales. Durably designed, the system will provide years of trouble free labs with components made of either cast-die aluminum or stainless steel.

WA-9314C ($2995) – Basic System for investigation electromagnetic interactions

WA-9316A ($3995) – Advanced System includes accessories for Brewster Angle and Bragg Diffraction experiments

2. Educational Spectrophotometer System

This very versatile system’s open design is ideal for education. When used with Capstone software, students can graph the spectral lines of gases; precisely measure the relationship between angle wave length and intensity; and analyze the transmission characteristics of filters and chemical solutions. The sensors can connect to PASCO’s full range of interfaces including the very affordable Wireless Airlink or the powerful 850 universal interface.

OS-8450 ($1912) – Includes Light and Rotary Motion Sensors and Optics Bench

OS-8537 ($1257) – Sensors and Optics Bench not included

3. Photoelectric Effect System

Planck’s constant is a central quantity in quantum mechanics and its discovery was one of the greatest breakthroughs in understanding the nature of light. With this system your students will be able to perform the photoelectric experiment to determine Planck’s Constant to within 5%. Students will also be able to verify that stopping voltage is independent of intensity and find the characteristics of the photodiode. Can be used with the 850 Interface and Capstone software

SE-6614 ($3156) – Basic System, includes Mercury Light Source with Hg tube

SE-6609 ($5666) – Basic System plus DC Current Amplifier and DC Power Supply

4. Electron Charge-to-Mass Ratio System

This system reproduces J.J Thompson’s landmark experiment to calculate the charge-to-mass ratio of the electron. A very sharp and visible electron beam within the vacuum tube allows for its radius (R) to be easily measured using the built-in fluorescent scale. The system also provides a measurement for the accelerating potential (V) applied to the electron gun as well as the magnetic field (B) produced from applying a current to the Helmholtz coils. With these measurements students can then accurately calculate the electron’s charge to mass ratio using the formula e/m=2V/B2R2.

SE-9629 ($6555) – Complete system with e/m tube and power supplies

Five Demonstrations That Show Why Physics Is So Cool!

1. Shoot the target. Load, Aim, Fire!

Your students will ask you to repeat this demo over-and-over again. The suspense of waiting for the target-to-drop and for the gun-to-shoot will mesmerize your students. At the instant the projectile is shot from the launcher the target is dropped. The ball will consistently hit the bull’s-eye of the falling target as both objects accelerate downwards at the same rate.
Shoot-the-Target System: ME-6853 ($604)

2. Ballistic Cart Accessory. Warning: may cause cognitive dissonance

Your students may not believe their eyes, but hopefully they’ll believe the physics. The moving cart will reliably catch the vertically launched ball every time regardless of the cart’s speed. This accessory works with your dynamics track system and is a great demonstration to show the independence of x and y motion.
Ballistic Cart Accessory: ME-9486 ($756)

3. Standing Waves. Strobe lighting is not just for rock concerts.

Dim the lights and let the show begin. Just like at the rock concerts, strobe lighting highlights the object of interest. The strobe also slows down the motion of the vibrating string so that students can see the features of the standing wave in greater detail. The Frequency and light intensity can be precisely adjusted for superior results.
String Vibrator: WA-9857 ($142)
Sine Wave Generator: WA-9867 ($511)
Strobe: ME-6978 ($681)

4. Magnetic Demonstration System. May the force be with you!

When raised and then released the swinging solid paddle stops instantly between the gap of the Variable Gap Magnet while the slotted panel sails straight through with no issue. Both paddles are made of aluminum, so why the difference? The answer …Magnetic Dampening! Diamagnetism and Paramagnetism, and Force on a Current Carrying Wire – are other great demonstrations of this comprehensive system.
Magnetic Demonstration System: EM-8644B ($812)

5. Ring Launcher. 10, 9, 8, 7…. 1, All Systems GO!

The ‘launched’ ring may not make it to the moon, but it will fly an impressive 2 meters straight up. The projectile is propelled by the Lorentz Force that arises from the interaction between the alternating magnetic field of the coil and the current induced in the ring. The Ring Launcher is a classic demonstration that includes 5 rings of different metals and dimensions.
Ring Launcher: EM-8817: ($1077)