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.

Glow Stick Kinetics

Want to illuminate the concepts of kinetics? Try Glow Sticks! Glow sticks are a very popular accessory around Halloween because they are cheap, portable and they give off a ghostly glow. But do students understand the chemistry behind the plastic tube that gives them light?

The “glow” from a glow stick is the result of a process called chemiluminescence – a chemical reaction that provides the energy to emit light. A glow stick is housing for two separate chemical solutions. The outer plastic chamber contains a mixture of a phenyl oxalate ester and a fluorescent dye. The inner glass vial contains hydrogen peroxide. When the glow stick is bent, the glass vial breaks releasing the hydrogen peroxide and activating the reaction.

Students familiar with glow sticks will remember that the light fades over time. This fading provides a perfect backdrop for introducing students to kinetics.

Initial Investigation

To study the glow stick fading, you can use a Light Level Sensor. Create a reaction vessel using a Calorimeter Cup and some black electrical tape.

Tape the Calorimeter Cup to ensure a dark baseline. Leave a hole in the top for the Light Level Sensor.

Create a graph of Light Level vs. Time using SPARKvue^® software. Remove the reactants from the plastic casing to eliminate interference with the Light Level Sensor.

CAUTION: The reactants are non-toxic and non-flammable, but contact with skin or eyes may cause discomfort. In case of contact, rinse with water. Reactants can also permanently stain clothing or furniture. Use appropriate precautions.

Carefully cut a hole in the top of the glow stick and pour the phenyl oxalate ester and fluorescent dye mixture into a small beaker. Then break the glass vial and pour the hydrogen peroxide into the small beaker.

Cover the reaction vessel with the lid and the Light Level Sensor, and start data collection.

The light intensity is decreased to half its original value after about 5 minutes.

Exploration

Now that it is established that the reaction can be studied with the Light Level Sensor, you can ask your students to explore factors that would affect the reaction. Some possible ideas for exploration could include:

Can you make the reaction brighter?
How does temperature affect the reaction?
Does the concentration, or amount of reactants affect the reaction?

For example you could have the students look at temperature. Create a hot water bath. Cut the top off of the glow stick and heat it up in the hot water bath.

Once the hot water bath with the glow stick has reached a sufficient temperature (about 60⁰C), pour some of the hot water into the Calorimeter Cup. Add a Fast Response Temperature Probe to the water in the Calorimeter Cup. Build a page with a graph of Light Level vs. Time and digits display of Temperature. Prepare the glow stick components as before and start data collection.

The initial light level is much higher than the room temperature glow stick, and the reaction happens at a much faster rate.

Using the Light Level Sensor, a Calorimeter and a glow stick provides a unique way to to explore kinetics with materials that are both familiar and fun!

Leaf Absorption Spectra

Fall is the perfect time of year for you and your students to investigate plant pigments. If the curriculum sequence doesn’t fit, you can always squirrel away some data for later! PASCO’s Wireless Spectrometer (and its free Spectrometry software) makes it quick and painless to do data collection and get full spectrum scans. No more warm-up time, tedious wavelength adjustments, or students waiting in line!

Download Free Lab Activity

Analyzing the absorption spectra is a popular lab activity that uses simple materials and can easily be extended into a student inquiry. PASCO’s biology team developed this new experiment to complement existing manuals and is available free to download.

Sample data showing the absorption spectra from several tree species (Tree of Heaven, Big Leaf Maple, and Black Oak leaves).

Enzyme Data-palooza

Many biology courses at every level start the year studying enzymes since they are integral to so many biological processes. No matter what your preferred enzyme and substrate, sensors can help you get more data, and better data, faster. As you can see, we like to catalyze with catalase since it’s widely available (in nearly all living things) and easy to process for lab use. For example, using the Wireless Pressure Sensor with a simple yeast suspension and 3% H₂O₂, students can begin collecting data for under $100/station – and look at how much data can be produced!

Figure 1. Each setup uses a 15 mm test tube, #1 1-hole stopper, 3 mL of 3% H₂O_2, and 1 mL of yeast suspension in a water bath at a set temperature.

Figure 2. SPARKvue monitors bath temperature while recording pressure data for each reaction.

Table 1. Rate of Reaction for Yeast and Hydrogen Peroxide

Condition	Trial 1 kPa/min)	Trial 2 (kPa/min)	Trial 3 (kPa/min)	Average (kPa/min)
3°C	0.280	0.155	0.733	0.389
15°C	0.547	0.633	0.589	0.590
25°C	0.981	1.015	1.134	1.043
35°C	1.591	1.732	1.643	1.655
45°C	1.045	0.941	0.899	0.962

Figure 3. Graph of Reaction Rate vs Temperature.

With more data, it’s possible to produce meaningful descriptive statistics with your students. This supports students’ math literacy and is useful to identify runs/groups that are outliers from the class data. While these outliers are often procedural errors, they can provide a useful springboard to inquiry. Ask students to determine why the group’s results differ. Are their results reproducible? If time allows, they can explore additional variables that can add to their understanding of protein structure, enzyme reactions, and even evolution.

The data above was produced using the Wireless Pressure Sensor. The protocol is the same for the Oxygen Gas Sensor; download the lab for your preferred approach.

Ocean Acidification

Ocean acidification is a byproduct of increasing atmospheric CO₂ levels around the globe, which is also causing climate changes. This global phenomenon can be difficult conceptually for students, but it is easy to model using sensors.

Here’s a quick video using the Wireless CO₂ and Wireless pH sensors:

Using a few simple materials, this quickly demonstrates to students what impact gaseous CO₂ can have on the pH of water as it dissolves. Ask students to consider the limitations of this model: How does it differ from earth systems? How could the model be improved?

Looking to extend this into a student lab? We’ve got an inquiry lab where students can act as the CO₂ sources and monitor pH with a sensor, while learning more about the chemistry behind ocean acidification.

Free Downloads:

Here are a handout and PowerPoint presentation that have been used when performing this activity as part of a PASCO workshop.

International Baccalaureate (IB): Inquiry-based Learning in Science

21st Century Science Teaching in the Context of IB Approaches to Teaching and Learning

Inquiry is a central idea in IB approaches to teaching. Learning through inquiry involves building on students’ prior knowledge, with a reduced emphasis on the teacher being the transmitter of knowledge. By engaging in effective inquiry, students develop skills in research, self-management, collaborative learning, communication, and thinking, as well as problem solving.

The IB curriculum supports using datalogging equipment since it has many benefits in accurately and efficiently collecting large data sets over periods of time.

PASCO’s wireless sensors have made data acquisition even more accessible by reducing costs and working seamlessly with any modern device. In the era of BYOD, a student’s computer, phone or tablet can serve as the datalogger, and data can be collected anytime and anywhere.

In today’s classrooms, not having sensors is like not having microscopes 50 years ago: there are still ways to address the content but students’ learning experience is highly compromised.

Scientific inquiry that uses appropriate technology gives students experience using the tools and practices of science, which prepares them to take their sciences beyond school.

For more information on how PASCO builds scientific understanding through technology–supported inquiry, click here to receive the complete white paper.

Be sure to check out Pages 16 & 17 for a complete list of the PASCO lab activities sensors that support the science practicals.

Abstract
This paper addresses how PASCO Scientific products and services support teaching and learning in IB programmes. Based on expert opinion, IB teacher interviews, and historical background, it uses IB guidance and curriculum materials to evaluate the IB approaches to teaching, pedagogy, and learning. This evaluation is used to the identify and demonstrate the support PASCO provides with science education solutions for MYP and DP programmes.

Introduction
The aim of this white paper is to communicate the clear synergy between International Baccalaureate (IB) programmes and PASCO products and services. This synergy is a result of a shared fundamental belief in inquiry-based teaching and learning, and in providing education that is active, contextual, and engaging.

When students take part in an authentic science experience using the technology and tools that scientists use, they understand the thrill of discovery and are better prepared for science literacy. A scientifically literate society is critical for nations to compete in a global marketplace and is an economic driver that enhances the lives of all citizens.

Education leaders around the world seek to transform their science programmes to support the growth of a knowledge-based economy, and PASCO is there to help. Developing students’ scientific literacy is a key step toward raising the standard of living, which prepares students to compete on a global scale. When students learn how to do science, and not just memorize facts, they develop competencies that help prepare them for job opportunities and the challenges that face all nations.

Countries around the world are racing to modernize their nations and prepare their people to compete on a global level. The key to their success lies in creating generations of educated citizens and skilled workers to drive economic development. It is through scientific literacy and with strong information, communication, and technology (ICT) skills that students can unlock opportunities on a global level.

Nova Scotia Department of Education visits PASCO Scientific

*Pictured above from left to right:* Chong Yang, Matt Murphy, Vivian Lemanowski, Christine Christensen, Brad Beveridge, Craig Ecclestone and Humberto Medina

We were delighted to host Nova Scotia Department of Education and Early Childhood Development’s Christine Christensen, the Provincial Science Consultant and Matthew Murphy, the French Immersion Science and Math Consultant at PASCO’s headquarters in Roseville, California last week. Joining Christine and Matt were AYVA’s President Dianne Beveridge, and Brad Beveridge, AYVA’s new Chief Operating Officer, along with Craig Ecclestone, our PASCO Product Specialist.

In 2016 Nova Scotia outfitted every elementary school in the province with a technology resource kit that included numerous PASCO sensors for use with iPads and Chromebooks. A core objective of last week’s visit was to discuss ways that both PASCO and AYVA can further support the use of the sensors in the classroom with train-the-trainer sessions, a customized Nova Scotia micro-site with Getting Started Resources and Videos, and grade-specific webinars.

We continue to be impressed with the exemplary efforts that the Nova Scotia Department of Education is making to provide professional development and support for science inquiry teaching practices at the elementary and middle school grade levels.

The visit also included a tour of the PASCO facility and a preview of some very exciting new products coming in the near future.

Enzyme Activity in AP Biology

Catalyze student learning in AP*^® Biology through an investigation of enzyme activity. By using a PASCO Wireless Spectrometer students can monitor the reaction in real-time and build a more robust data set.

Students can investigate the decomposition of hydrogen peroxide into water and oxygen by using peroxidase (found in filtered turnip extract). With a small amount of Guaiacol in solution the reaction can be easily monitored in the Wireless Spectrometer because it changes color as it oxidizes.

After creating a blank and calibrating the Wireless Spectrometer on the Analyze Solution tab, select the target analysis wavelength of 470nm.

Figure 1. Setting the analysis wavelength in the Spectrometer Software.

Students can then go to the Time tab to monitor the reaction at 470nm. Prepare the reaction in a standard cuvette by adding the substrate (H₂O₂), pH buffer, and Guaiacol. Once the enzyme extract is added the reaction proceeds quickly, so make sure to test the reaction before the lab and dilute the enzyme extract if needed.

Figure 2. Monitor the reaction in real time before analyzing and comparing runs from various trial groups.

After establishing a baseline, the rest is inquiry! By changing the pH buffer, temperature, or enzyme and substrate concentrations students can quickly explore the reaction and identify the optimal conditions for turnip peroxidase. Data can be analyzed in the software to determine the rate of reaction or exported for aggregation and further analysis. This is a great lab to introduce or reinforce concepts around protein structure and specific nature of the enzyme-substrate complex. Students can also compare the catalyzed and uncatalyzed reaction to see how the energy of activation is lowered by these (seemingly magic) biological molecules!

Download a Free Copy of the Lab Handout

Figure 3. Sample data from investigation of Peroxidase reaction at pH 2, 4, 7, 10, 12.

* AP is a registered trademark of the College Board, which was not involved in the production of, and does not endorse, this product or activity.

Untangle Your Circuits!

Making the leap from circuit diagrams to functioning circuits has never been so clear or intuitive. Circuits can be easily built and tested enticing students to more thoroughly explore the behavior of electricity. Your students will no longer be frustrated trying to trace out the electrical pathway through a nest of wires.

Supports inquiry learning – circuits can be easily modified and be quickly swapped out and rearranged

Compatible with both traditional and computer based labs – works with PASCO’s sensors as well as traditional Volt and Ammeters

Classroom management is a breeze – Storage is made simple with the included

Grattenels case and nesting trays

The 8 cm by 8 cm modules ensure that all students in a group can clearly see the completed circuit
Physical Components (resistors, batteries, switches, etc.) with identifying electronic symbols are visible on the surface of the modules
At a glance errors in a circuit can be quickly found without checking each connection

The Basic Kit includes enough modules to do 5 basic experiments:

Ohm’s Law
Series/Parallel Circuits
Batteries & Bulbs Circuits
Switches/Open/Closed Circuits
Electric Power & Energy

The Advanced Kit includes the Wireless Current & Voltage Sensors and modules for 7 additional experiments:

Kirchoff’s Laws
Electromagnets
Electromagnetic Induction
RC & RL circuits
Variable Resistance
LED Circuits
Electric Motors

Rhonda & Craig Invade LA – NSTA 2017 Recap

We were thrilled to attend this year’s NSTA national conference in Los Angeles.

Our first destination was the exhibit hall where PASCO had a very lively booth with several interactive displays. By far the biggest hit was the ‘Match Graph’ challenge with a super-sized Smart Cart. Who knew that learning could be this much fun! Check out the video to see my less than stellar attempt.

PASCO’s booth was fun, however, the real action was in the teacher facilitated workshops. In total PASCO had 20 unique hands-on sessions that were over flowing with enthusiastic teachers. Time didn’t allow us to see all the sessions, but we did manage to squeeze our way into a very energetic session on the new Modular Circuit Kits. Teachers had a great time ignoring instructions and spent most of the session designing their own unique circuits – obviously investigative learning is not just for students.

We were also fortunate enough to get a seat at PASCO’s workshop session on climate change. The session featured several hands-on modeling activities, including an investigation where teachers used the Wireless pH sensor to monitor the mitigating effects of natural buffers on acid rain. The biggest hit of the session was seeing PASCO’s new Wireless Carbon Dioxide sensor in action. Teachers were excited to discover that a reliable, practical and affordable way to measure CO2 has finally arrived.

Over the next week we’ll share some more videos on our adventures at the conference.

1-877-967-2726

1-877-967-2726