chemical education

Review: Chemistry Sets fit for the 21st Century.



As a kid I loved my chemistry set. Many an afternoon was whiled away in my dad’s shed, totally ignoring the set’s instructions and randomly mixing the contents of the various bottles. To be honest I can’t really remember learning much chemistry, beyond the fact that it was possible to generate some pretty noxious fumes.

I guess its that sort of behaviour that rang the death knell for those sets of old. Today’s high street chemistry offerings seem to have been sanitised to the point of tedium, whilst some even proclaim to be chemical-free (shudder).

But there is hope. MEL science have launched a product that brings the chemistry set smack into the 21st Century. And I was pretty excited to get my hands on one.

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MEL chemistry starter pack and 5 experiment boxes.

MEL chemistry is supplied via a subscription model. The starter pack is £29.95, and includes some glassware, safety specs, a solid fuel burner, a google-cardboard VR clone, a tray, a neat macro lens that clips onto a smartphone and other bits and bobs. On the face of things this looks a little steep, but you should also  take into account a really very good IOS/Android app, which shows various 3D representations (when used with the VR goggles) of all the reagents you are likely to encounter later.

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Tin set unboxed

All the experiments are sold separately, at £9.95 per experiment set, with 3 delivered each month. The idea being that you each month you receive a new kit. This seems really very reasonable to me, and is just the sort of model that maintains the excitement. Fresh chemistry coming through the door each month should keep up the interest.

Each experiment was accompanied by a very good instruction card and a detailed online page. The webpage goes into far more depth that you would expect for the target 12+ age group. But its all clear and well written. A very minor criticism is the commentary to the videos, sometimes the heavy (Russian?) accent makes things a little difficult to follow.

We (a small Lorch and I), cracked open the ‘Tin set’ and fired up the accompanying video. Everything is very well packaged with a lot of thought going into how kids should dispense solutions  safely. My lab assistant, for this experiment, has quite a reputation for knocking fluids flying, but in this case, and despite a couple of up ended bottles, nothing was spilt.

So over to the real action. The ‘Tin set’ contains two experiments. First, the tin hedgehog, which simply involves dropping a zinc pellet into a solution of tin (II) chloride. Tin crystals quickly form on the pellet, these are quite small and would be difficult to see without the help of the clip-on macro lens. So with the expanding crystals captured live on my phone’s screen  my co-experimenter was quite impressed.

Then we moved on to the tin dendrites. Again the method was easy for my pre-teen helper to follow. And this time, as the beautiful branches of tin struck out across the petri dish there was some genuine amazement in the room.

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Tin hedgehog, as seen via the kit’s macro lens.

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Tin dendrites

     

So far so very impressed. By linking all the experiments with excellent online and smart resources they should really engage the budding chemist and ensure they learn a heck of a lot more than just how to gas themselves. In short they are fun, safe and bang up to date.

I’ve got previews of another 4 experiments to try and will let you know what I think. If they are up to the same standard I’ll be signing up for the other 34.

EDIT: Note, a previous version stated that the sets cost £9.95 per month. This should have read £9.95 per experiment set. The text has been altered to correct this.

By October 27, 2015 2 comments chemical education

Spread the word about chemistry & don’t fret the chemophobia

   

At times chemists can feel rather maligned. But according to the RSC’s study of the UK public’s perceptions of chemistry we shouldn’t be quite so worried about what people think of us.  We do however need to get out there and let people know what we do.

The other sciences seem to get pride of place in the medias science pages and TV shows. Whilst chemistry has no celebrity singing it’s praises, not a single chemist made it into Science Magazines  50 science stars on Twitter, and chemistry news just doesn’t get the same coverage as the big physics projects (even when the physics project was all about landing a chemistry lab on a comet).

As a profession we think we do some pretty important work. After all every modern pharmaceutical, synthetic material, cleaning product, fuel, battery, ink and electronic device contains our handy work. Which is why we get upset when an advertising campaign emblazons the dreaded words “Chemical-free’ across some product or another.  Or the likes of The Food Babe, decides to start an uniformed campaign against an additive based on little more than the fact she can’t pronounce it.

Sometimes we (I) throw our toys about the pram and start ranting about how everything is made of chemicals and how chemophobia is rife. God knows bloggers have written enough posts about it, including a comical ‘paper’ in Nature Chemistry. However, we should settle down, because the Royal Society of Chemistry has commissioned a comprehensive study of UK public’s perceptions of chemistry, chemists and chemicals. And it seems many of those (mine included) irate blog posts got it wrong.

I’ve been able cogitate about what it all means as I got an an advanced copy of the findings and have had time to discuss them with the RSC. So here’s my potted summary and a few conclusions.

Perceptions of perceptions of chemistry: First off the RSC asked it’s members about how they thought the public perceived chemistry. And sure enough most expected a negative attitude. The fear of chemophobia amongst chemists was certainly commonplace. But when the RSC turned to the public chemophobia didn’t materialise in anywhere near the expected levels. Instead …

Perceptions of chemicals:Chemophobia is not commonplace. Less than 20% of the public thought that all chemicals are dangerous or harmful. Most people really didn’t have strong feelings about chemicals one way or another. And 60% knew that everything is made of chemicals. This is despite the use of ‘chemical’ to mean something dangerous being very common.

Perceptions of chemistry: Here 59% believe the benefits of chemistry are greater than any harmful effects (as compared to 55% for science). And once again most people were pretty neutral about chemistry as a subject.

Perceptions of chemists: It turns out people just don’t know what we do. This is made all the worse, in the UK, by retail pharmacists being universally known as chemists.

Don’t fret the chemophobia

There’s an important message here about what’s going on when ‘chemical’ is used pejoratively. For most people ‘chemical’ has a double meaning. So we shouldn’t get upset when ‘chemical’ is used as a short hand for toxin or poison. I know I’ve written plenty that’s contrary to this, but the RSC’s study has really changed my thinking. People are quite capable of holding two meanings of ‘chemical’ in their minds and we should just try and ignore the use of the one that soooooo grates. In fact it may even be counter productive to try and combat our perceived misuse of ‘chemicals’. As the RSC study puts it…

“People’s views of chemicals do not impact their view of chemistry or chemists. But if chemists talk about chemicals all the time, especially in trying to combat inaccuracies in the views of others – we risk activating existing fears.”

Chemists aren’t being tarnished with the chemicals = danger association. But by continually banging on about how chemicals are in everything we run the risk of being alienating our audience. Luke Gammon put’s it very well.

Don’t denigrate, belittle or “punch-down” – remember to laugh with, not at – lest we lose the battle for the public perception of “chemicals”.

So here’s me hanging up my #chemophobia hash-tag. And conceding that Luke, Renee and Chemtacular probably had the right idea (check our their blogversation)

There’s a void we need to fill

However the overwhelming message is that there is a void in the public’s perceptions of what it is we do. And it’s a gap that we should all do our best to fill. That means that we all need to do our bit, whether on social media, in blogs or even at parties. We can all tell people about what we do. There’s a great appetite for science out there, we shouldn’t assume that people aren’t interested in what chemists get up too and we certainly shouldn’t fear a negative reaction from them.

To go along with the study the RSC have also published a communications toolkit which summaries their main findings and contains some tips for how to get the wonders of chemistry across. Please go and take a look and then spread the word.

And join in the discussion on twitter with the hash-tag #chemperceptions.

 

My Extra Credit Assignment: Turn a General Chemistry Topic into a Science Museum Exhibit

When traveling, I always make a point to explore local science museums. I look for engaging exhibits that explain scientific concepts in informative and fun ways. One such exhibit at the Science Museum of Minnesota asks participants to create carbon nanotubes using foam connectors. A few friends and I used our advanced degrees to produce the example shown below (sorry for the potato quality).

The exhibit engaged people of all ages in different ways. Just behind the exhibit you can see the little guy who, moments after the picture was taken, learned all about tearing carbon nanotubes apart while deploying a rather impressive Godzilla impression.

Nanotube

Since becoming a teacher I have a new appreciation for science museum exhibits. They are a literal manifestation of Einstein’s philosophy: “If you can’t explain it to a six year old, you don’t understand it yourself.” The best exhibits make the explanation entertaining too.

So, towards the end of this spring semester when my general chemistry students requested an extra credit assignment, I knew exactly what to assign. I asked them to take one of the concepts they learned in general chemistry and create a science museum exhibit to explain it.

The assignment allowed unlimited space and budget. I was less concerned about reality and much more interested in seeing their knowledge and creativity. In the end I was blown away by their creations and would like to share a few.

Dipole-dipole Board

Dipole-dipole

The above exhibit, created by Taylor Trammell, showcases intermolecular dipole-dipole interactions. Her display contains many magnets–representing molecules–with two opposing sides, one positively charged (north pole) and one negatively charged (south pole). All of the magnets/molecules are free to rotate, except for one. Museum visitors can press a button and control the orientation of that one ‘molecule’. As it’s orientation changes, the other ‘molecules’ will reorientation to maximize dipole-dipole interactions and minimize the energy within the solvent.

A visitor could also walk up to the board with a strong bar magnet and introduce only it’s north or south pole to the magnet-filled board. That would represent the solvation of cations or anions through ion-dipole interactions. Taylor may not know it, but she found a fun way to introduce the solvent reorganization associated with Marcus Electron Transfer Theory.

Collision Theory Booth

According to the Collision Theory of Reactivity, for a chemical reaction to occur the molecules must: 1) collide, 2) have enough energy to make and break bonds, and 3) have the correct orientation when they collide. Emily Nabong demonstrates these rules of engagement through a museum exhibit that repurposes an amusement park throwing booth. Instead of milk jugs or balloons, the target is a Velcro-covered molecule. And instead of baseballs or darts, visitors throw ‘molecules’ with different geometries and Velcro coverage at the target.

If the molecule is thrown with too little momentum or too little accuracy it will not hit the board (collide). Also, if the molecule hits the board with the wrong Velcro alignment it won’t ‘stick’ (correct orientation). The ‘reaction’ will only occur if the molecule is thrown hard enough and with the right orientation.

Collision

Amorphous vs Crystalline Solids

Miranda Ave introduced an interactive “build your own solid” exhibit that demonstrates the difference between amorphous and crystalline solids. It’s comprised of two building stations. The first station offers Magnetix (below left), which have curved connectors representing bonds and metal spheres representing atoms. The second station offers Tinker Toys (below right) with only one rod length (bonds) and wood circles that connect at 90° positions (atoms).

Solids

Any structure built with the Magnetix will lack long-range order like in an amorphous solid. In contrast, a structure built with the restricted connectivity of the Tinker Toys will have a continuous, repeating pattern like those observed in crystalline solids.

Tearing apart these structures will also help demonstrate differences between amorphous and crystalline solids. Tinker Toys break apart in a ridged manner along cleavage lines while Magnetix structures break in random places.

The building stations will also be accompanied by a display with both crystalline and amorphous solids as well as an atomic picture of their structures.

Viscosity Race

Both Gabby Vega (below left) and Erum Kidwai (below right) proposed races between liquids to demonstrate differences in viscosity. They envisioned racetracks with several lanes, each labeled with a molecular structure. Museum goers would pick their ‘horse’ or lane and then watch as liquids ‘race’ down the track. Afterwards, each solution would be unveiled and the intermolecular forces dictating the viscosity and flow rates of the liquids would be explained.

Viscosity

Boyle, Lussac and Avogadro

Jessica Metzger’s museum exhibit set out to teach people about the relationship between temperature, volume, number of moles of a gas, and pressure. She proposed three different interactive stations. The first (left) contains a cylinder connected to a pressure gauge with a plunger that can be pushed or pulled. When the plunger is pushed (or pulled) and the pressure increases (or decreases), the reading on the pressure gauge will increase (or decrease) just as predicted by Boyle’s law.

The second cylinder (middle) is completely enclosed and placed on top of a heating element. When the visitors press the button a red light will turn on indicating that the chamber is being heated. As the temperature increases, the pressure will increase in accordance with Lussac’s law.

The third cylinder (right) will be taller than the other two with a lid that can move up or down without allowing gas molecules to escape. The station will be equipped with a button that, when pushed, releases compressed air into the cylinder. So, when the button is pressed, the metal lid will move up and increase the cylinder’s volume to accommodate the newly introduced gas molecules (Avogadro’s Law).

PV = nRT

Electronegativity and polarity

Carolin Hoeflich proposed an exhibit to introduce the concept of electronegativity and polarity. The exhibit includes a table with a soft foam cover and blocks representing the elements. The blocks are weighted so that electronegative elements are heavier. Museum-goers can arrange the blocks into molecular structures before dumping marbles–representing electrons–onto the table’s surface. The heavier elements will sink deeper into the foam and therefore ‘attract’ a larger number of marbles. When stepping back and looking at the structure as a whole, museum-goers will see that more marbles = more electronegativity. It’s also a fun way to visualize the dipole moment of a structure.

Electronegativity

Osmosis touch screen

Hunter Hamilton introduced a touch screen exhibit to demonstrate the principles of osmosis and osmotic pressure. Visitors will use the screen to create an environment with more or less ions (red spheres) and one of three possible ‘membrane’ options: 1) no membrane, 2) permeable to water but not ions, and 3) permeable to water and ions. Once all selections are made, the visitors presses GO and observes which direction water and ions move in their environment.

Osmosis

Le Châtelier’s Principle

Another touch screen exhibit, by Kelly Wyland, covers Le Châtelier’s Principle. Her screen displays an equilibrium with colors assigned to the reactants and products. It then asks users to predict the color change upon perturbation. After a prediction is made, the screen will show an animation that adds or removes reagents from the reaction mixture’s beaker. The color change of the solution will coincide with the concentration shifts to reach equilibrium.

LCP

Reaction Coordinate Slide

I’ve saved the largest and most interactive exhibit for last. Nathan Horvat designed an exhibit with two slides that represent an exothermic and endothermic reaction coordinate diagrams. Children (maybe adults?) would start on the platform in the middle (as reactants) and climb one of two ladders representing the activation energy to the transition state before sliding down to the landing pads (products).

The ladder/slide to the left (or right) is for an endothermic (or exothermic) reaction because the end point is higher (or lower) in energy than the starting point. One thing that I found fun about this exhibit is that, while viewing it in action, you’d likely notice more children choosing the exothermic slide because the endothermic one requires more work for less return. In a statistical fashion, the children would find the product that’s more thermodynamically favorable.

rxn coordIn closing, I want thank my students for a great semester and to share my appreciation for the students who designed these exhibits. It was a pleasure to teach them and to see them come up with such creative ideas. I hope one day, during a random science museum visit, I find one of these exhibits in action.