Cooking vs Chemistry

Chemistry is like cooking ... just don't lick the spoon.

Cooking can be used to help students understand fundamental chemical concepts, like chemical equations and stoichiometry.

Read how at https://www.ausetute.com.au/ausenews/ausenews.html

Vegan Leather

 My local bag shop is now full of bags that proudly state they are made out of "Vegan Leather".

Vegan leather? Surely that is an oxymoron?

    vegan = not consuming/using any animal products

    leather = animal skin that has been tanned or undergone a similar process.

So what is "vegan leather"?

It turns out that the majority or "vegan leather" is just poly(vinyl chloride) (PVC) or poly(urethane) (PU), polymers produced from reagents derived from fossil fuels. Handbags made out of PVC (vinyl bags) have been around for decades, and have been a much, much cheaper option than expensive genuine leather bags.Until now! By re-branding vinyl bags as "Vegan Leather" suppliers can increase the price, capitalizing on the significant consumer trend toward "vegan" products.

I live in a city that is trying to ban the use of single use plastic items including shopping bags and straws etc which end up in landfill and stay there for (not-quite but almost) ever. How do you feel about your new plastic "vegan leather" handbag? When it starts to fall apart (anything from about a month to a year or so depending on use and quality) and you throw it out, do you feel that you have done your bit for the environment?

If you live in a country where there are growing demands to reduce coal-fired power generation, and reduce the use of fossil fuels in cars etc, in order to reduce the community's "carbon footprint",  how do you feel about your fossil fuel based "vegan leather" bag?

It isn't "vegan leather". It is plastic.

vegan leather bag = plastic bag

Slime

One of the most popular school holiday "science projects" is to make slime by adding an aqueous solution of borax to PVA glue. Young children, and adults, can have hours of fun playing with this oozey slime, discovering some of its interesting properties along the way.

But what is slime and why should we be interested in it?

Read this edition of AUS-e-NEWS to find out more.

Subscribe to AUS-e-NEWS at https://www.ausetute.com.au/ausenews.html

Decline in Student Entrollments in Academic Subjects

 This fabulous graph of enrollments in the most popular HSC subjects over time was published in the Sydney Morning Herald today:

 

In the newspaper article, concerns were raised about the declining number of physics students, and the fact that only 22% of these students were female.

What I see in this graph is a general downward trend in enrollments of most of these subjects. You'd be particularly concerned about your future employment prospects if you teach Ancient History, for example.

What I don't see in this graph are any dramatic increases in enrollments, so, where have all the students gone?

Are overall student numbers declining (and hence enrollments in individual subjects are declining)?

Or, are there other less popular subjects with massive increases in student enrollment?

If we are concerned about the lack of females in Physics (22% female) why are we not equally concerned about the lack of males in Biology (36% male)? Or the poor showing of males in English Extension 1 (33%) and 2 (29%). 

We are still seeing student numbers divided along gender lines. So here are some "not-at-all-surprising" stats ...

• 5% of students in "Dance" are male
• 5% of students in "Textiles and Design" are male
• 8% of students in "Human Services" are male
• 10% of students in "Community and Family Studies" are male
• 5% of students in "Construction" are female
• 5% of students in "Electrotechnology" are female
  
• 6% of students in "Automotive" are female
• 9% of students in "Engineering Studies" are female
• 10% of students in "Software Design and Development" are female 

 And if I went back 30 or 40 years, I'm guessing the percentages would not be so very different.

What have we achieved in education in 4 decades?

Polymerize or Polymerise?

A polymer is produced when lots of monomers bond together. Monomer has Greek roots, mono meaning one and mer meaning parts. Polymer also has Greek roots, poly meaning many and mer meaning parts.

So  we can form a verb that means to produce a molecule of many parts. Because the words monomer and polymer have Greek roots, we should use the "ize" suffix, that is, polymerize. Yet, particularly in Australia,  the Latin "ise" suffix is used to produce the verb polymerise.

The word, polymerise, would have a Greek root (poly, many), a French root (mer, sea), and a latin suffix (ise). This would appear to suggest that to polymerise would be to make many seas. On the other hand, a monomer would be just one sea.

Merde!

Ionize or Ionise?

 In chemistry we have a verb to describe the process of producing ions, but how do you spell it?

Is it ionize? (rhymes with prize)

Or is it ionise? (rhymes with surprise)

The root of the word is Greek, so according to my school grammar teacher, the suffix should be "ize". The preferred IUPAC spelling appears to be ionize, and hence ionizing and ionization.

Similarly, we also have a verb to describe the process of producing atoms, also from a Greek root, so the preferred spelling should be atomize, not atomise. Hence we form the words atomizing and atomization.

I'm sure we'll continue to see the alternative spellings with an "s" rather than a "z" but they won't get you a Nobel Prise. Surprize!

Underwater Bubbles

 A backyard experiment you can do that will help you see Boyle's law in action.

https://www.youtube.com/watch?v=aHvGtWXTdso

 You will find more information in the feature article about SCUBA diving in the June 2022 issue of AUS-e-NEWS.

Let's Go SCUBA Diving

In 2021, Mitchell Goodwin, an experienced SCUBA diver, was diving off the coast of Mandurah in Western Australia. According to the report in the "West Australian", he descended to a depth of 42 m and stayed at this depth for 27 minutes. On his ascent, he made one decompression stop. When he got back to the boat he felt nauseous, lost his hearing, his sight, and blacked out.

What had gone wrong?

Read more in the June 2022 edition of AUS-e-NEWS.

Subscribe to AUS-e-NEWS, AUS-e-TUTE's free quarterly newsletter for chemistry students and teachers, at https://www.ausetute.com.au/ausenews.html

Periodic Table update

 IUPAC has updated the periodic table.

Time to update yours .... https://iupac.org/wp-content/uploads/2022/05/IUPAC_Periodic_Table-04May22.pdf

Australian Curriculum and Year 9 "Science"

 Last year I was writing questions for an Australian Years 9-10 Science textbook when I first came across the "gamma decay" problem.

The textbook authors stated that there are 3 types  of radioactive decay: alpha, beta and gamma (which is kind of OK for Year 9 or 10 science). They wanted to provide an isolated example of each type, that is, an example of alpha decay, an example of beta decay, and an example of gamma decay. Which is where the problem lies. Giving an example of alpha or beta decay is easy, just ignore any other possible radiations when you do it, which is the "traditional" method for teaching nuclear decay to Years 9 or 10, or indeed Year 11 chemistry (and yes, physics teachers are probably horrified, and rightly so, IMHO). But, you can't do this for gamma decay unless you want to talk about "excited states".

Which brings us to version 9 of the Australian Curriculum for Year 9 Science which states,

"describing in simple terms how different unstable isotopes decay such as radon-222 releasing an alpha particle, iodine-131 releasing a beta particle and cobalt-60 releasing gamma radiation to form stable atoms"

Alpha decay of radon-222 and beta decay of iodine-131 ... OK, can do.

Gamma decay of cobalt-60 ? Problem! Cobalt-60 decays by emitting a beta particle to produce an excited state nickel-60 atom. Excited state nickel-60 loses energy by emitting high energy gamma ray and relaxing back to a ground-state nickel-60 atom. But, we can't use this as an explanation because the introduction to excited states won't occur 'til, possibly, year 10 (when they do flame tests).

Has the Australian Curriculum been proof-read?

I think not. Further evidence of the writer's (or writers') slipshod approach to "science" is evidenced in this "interesting" extract (also for Year 9)

"investigating how radiocarbon and other dating methods have been used to establish that First Peoples of Australia have been present on the Australian continent for more than 60,000 years"

Problem 1: radiocarbon dating is pretty useless for anything older than about 40,000 years old, so it would be worse than useless for artifacts said to be 60,000 years old. 

Problem 2: where is the SCIENTIFIC evidence that Australia has been inhabited by humans for "more than 60,000 years"? Surely if you are going to make a statement like this, and force SCIENCE teachers to teach it, you need to support the statement, just a link a two, some references, to some SCIENTIFIC studies would be useful. 

So, here's what I think I know ... Mungo man/mungo woman are thought to be about 40,000 years old (give or take a few thousand). Blackened rocks at Moyjil are thought to be about 125,000 years old, but not linked to human habitation (that I'm aware of). The Pilbara petroglyphs have a wide range of dates depending on who provides them, but they also seem to be scientifically dated between 40,000 and 50,000 years. 

My problem is that I'm not an anthropologist, I know a little bit about chemistry (Chemical Sciences), a bit less about geology (sorry, Earth Sciences), even less about physics (AKA physical sciences), and practically nothing about biology (sometimes called a science), and hence I am NOT in a position to either a) know how long Australia has been inhabited for, or

b) to teach anything about this 

... and I suspect most SCIENCE teachers in Australia would fall into the same category.

AC: Australian Curriculum or Australian C_ _ p?

Converting Between Concentration Units

The concentration of carbon dioxide dissolved in water is about 0.000011 mol/L, while the concentration of carbon dioxide in blood is about 1100 ppm. It is not easy to tell which of these two solutions is the most concentrated because they are in different units. However, if we were to convert the concentration of carbon dioxide in water from mol/L to ppm, we could easily compare these two concentrations.

AUS-e-TUTE has just added a new tutorial, game, test, drill, prac, flashcards, quiz, worksheet wizard, and problem solving template to help!

 

Members should log-in to use these new resources: https://www.ausetute.com.au

 

If you are not an AUS-e-TUTE member you can view the tutorial for free at https://www.ausetute.com.au/concconv.html

Chinese Milk Scandal

 When we buy food from a shop, we assume that food is safe to eat, but sometimes it isn't!

In 2008 six babies died from kidney stones and an estimated 54,000 babies were hospitalized in China after being fed "Infant Formula" (baby milk) adulterated with melamine, an industrial chemical. It is thought that about 300,000 babies in total were affected by what came to be known as the "Chinese Milk Scandal".

Why was melamine added to Infant Formula? And why did it take so long to discover its addition?

Read more in this edition of AUS-e-NEWS:

Subscribe to AUS-e-NEWS at https://www.ausetute.com.au/ausenews.html

 

2022 World Science Festival Brisbane

 World Science Festival Brisbane 9-13 March 2022. 

https://www.worldsciencefestival.com.au/

Slim pickings for chemistry (yet again this year), unless you are a tiny child who thinks making slime is the highlight of your day. 

With Australia moving towards battery storage for electricity, why are isn't there an "event" discussing big lithium-ion batteries, or the proposed next-gen alternatives? 

Or fuel cells? 

Queensland Government has a strategy for the "hydrogen industry", so where is the "event" discussing the production and use of hydrogen in a so-called "hydrogen economy"? 

How about an "event" that discusses water treatment? desalination? 

An "event" that discusses the "effectiveness" of home water filters (and dare I suggest face masks)? 

What about an "event" to talk about "food fraud", what it is, how it is detected, what we can do about it. 

Recycling plastics? Compostable polymers? Soluble polymers? 

It's not hard to think of relevant chemistry topics for a "science festival". 

 

South Australia sets a poor example

 I've always admired South Australia for its innovative and interesting chemistry syllabi, and it's great that females are being featured in chemistry labs, but the current image on their website is a big fail in terms of chemistry education.

 

https://www.sace.sa.edu.au/web/chemistry

 

Can you see any problems with this photo?

(revise "Safety in the Lab" at https://www.ausetute.com.au/safety.html)

Shapes of Melting Ice

 What shape is submerged ice as it melts?

That depends on temperature apparently ..

 Which suggests that we can infer water temperature in nature by observing the shape of its melting ice.

Scott Weady, Joshua Tong, Alexandra Zidovska, and Leif Ristroph (2022); Anomalous Convective Flows Carve Pinnacles and Scallops in Melting Ice. Phys. Rev. Lett 128(4)  https://doi.org/10.1103/PhysRevLett.128.044502

SI Units for Chemistry Students

What is an SI unit?

What is the SI Unit of mass?

Is ms a metre second or a millisecond?

Is V the symbol for electric potential or volts?

The answers to these and other questions about SI units can be found at https://www.ausetute.com.au/siunits.html

AUS-e-TUTE members should log-in to use the new SI Unit learning resources, including digital flash cards.

Mass Concentration (m/v)

 There are lots of ways to measure concentration in chemistry.

One method is to divide the mass of solute by the volume of solution: m/v

This is called a mass concentration and common units for mass concentration are g/L or g L^-1

AUS-e-TUTE has just added new teaching and learning resources for mass concentration calculations (game, test, drill, quiz, worksheet and problem solving template).

Members should log-in to use these new resources.

Non-members can go to the "free-to-view" tutorial at https://www.ausetute.com.au/massconc.html

Food Fraud in Australia?

Congratulations to Dr Michael Smith, Associate Professor Mahmud Ashraf, Professor Chris Austin
and Associate Professor Rebecca Lester of  Deakin University on the publication of "Product fraud: Impacts on Australian agriculture, fisheries and forestry industries" (November 2021). This report gives a good, concise, overview of known recent agricultural product fraud from all over the world. While it can make for scary reading, it is a reminder to stay vigilant when buying food. Here is a little taste of what you will find in the report,

"Turmeric is considered highly vulnerable to food fraud, with
frequent incidents of contamination with lead chromate (a
yellow colourant) reported. A study found that seven of nine
turmeric-growing areas in Bangladesh showed evidence
of turmeric adulteration with lead chromate. Levels of lead
exceeded national limits by up to 500 times (24-9-19)."

You can download a copy of the report at the AgriFutures Australia website: https://www.agrifutures.com.au/product/product-fraud-impacts-on-australian-agriculture-fisheries-and-forestry-industry/

Examples of food fraud can be used when teaching chemistry. Students can calculate the concentration of milk or fruit juice after it has been fraudulently diluted, and then compare that to what is stated on the nutrition panel product label. You can learn a lot about the properties of chemical compounds and mixtures by making a fake egg or fake milk. You could used the adulteration of "manuka honey" to teach spectroscopy, or the melamine (1,3,5-triazine-2,4,6-triamine) in milk scandal to teach percentage composition or volumetric analysis. The pedagogical possibilities are limited only by the resourcefulness of the food fraudsters.

If you are looking for some more inspiration, try "Sorting the Beef from the Bull: The Science of food fraud forensics" (Evershed, R., and Temple, N, 2017). And yes, I may have bought it because it has such a great title ... you all know me too well 😉