Excellent Advice for Chemistry Teachers

 The WA 2022 ATAR course examination report for Chemistry offers some excellent advice for all teachers of chemistry,

"Teach general concepts from first principles so that students can apply concepts to unfamiliar situations, not just write everything they know."

If you had shown this to me in 2019, I would have been shocked to think that any chemistry teacher wasn't teaching concepts from first principles, but COVID19 really did fundamentally change the way teachers were forced to teach, and how students were forced to study. "Remote learning" encouraged a return to the "bad-old-days" of rote learning "facts" and "how-to"s as a means to obtaining an end (success in exams). Unfortunately, once these electronic measures had been put in place (rather hurriedly in most cases), nobody seems to want to revisit this hasty construct and replace it with something better. There is a huge opportunity here to begin teaching chemistry as a science, using the scientific method, but no, we continue to teach students how to answer exam questions.

This is not education, it is training. And it is training of the worst kind since the ability to answer exam questions is not very useful in the workforce or in adult life.

Heed the advice, "Teach general concepts from first principles so that students can apply concepts to unfamiliar situations", and bad training becomes great education.

Making it harder to cheat

Here is the problem: teachers want to engage their students with interesting demonstrations and activities to motivate them to think about  a scientific concept. Students, on the other hand, just need a good mark on the tests and assignments so they can become a doctor, or a lawyer, a cobbler or a candlestick maker, etc.

As the technology available to students to help them answer their assignment questions gets better, teachers need to think about how to structure questions to make students think, rather than just google the answer.

Here is an example of a pretty standard sort of test/assignment question; What properties of aluminium make it suitable for use in cooking pots.  Give a disadvantage of using aluminium for pots.

If you copy and paste that into google, there are 2,090,000 results, and the top of the page will read, "Aluminum is lightweight, cheap and very good at distributing heat. It doesn't retain heat particularly well though, so the temperature will fluctuate as food is added to a hot pan. It's also the softest metal on our list, so it will scratch and dent pretty easily."

Assignment done! No thought required!

So we need to re-structure the question. How about this...

On the planet P42da, the element potsnpanium is used to make large pots in which the P42daians heat soup to above the boiling point of liquid water at 1 atmosphere. What properties of potsnpanium make it suitable for this purpose. Give an example of a safety precaution the P42daians should take when handling potsnpanium pots. Describe a way to reduce this hazard.

Copied and pasted into google this yields 0 results and a heap of useful suggestions:

"

• Make sure that all words are spelled correctly.
• Try different keywords.
• Try more general keywords.
• Try fewer keywords.

"

Might force some students to have a think about it.

Corrosion in the Kitchen

 There are two jars of nuts in the kitchen. One jar is always filled with unsalted nuts while the other jar is always filled with salted nuts.

Can you tell which jar holds the salted nuts?

Visit Corrosion Chemistry Tutorial (ausetute.com.au) for more information.

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?