It’s been exactly three years since I uploaded the original banana poster.
In 2014, I soon followed up with podcasts, radio appearances, press interviews, a T-shirt Store and twelve more fruit ingredient labels. I’ve done six more customised fruit ingredients labels for private clients. The images have since appeared in textbooks, corporate promotional material, YouTube videos, T-shirts, mugs and aprons.
Momentum built in 2015. Parodies emerged online, and a copycat image appeared in one Chemistry textbook. I started writing about chemophobia and consulting with experts on how to address the issue. In short, it’s very, very complicated, and has deep evolutionary origins. I set a goal to understand chemophobia and provide a roadmap to tackle it effectively.
In 2016, my voluminous OneNote scribblings turned into a book. I have a first draft saved on OneDrive (thank you for keeping it safe, Microsoft) and I’ll be proofreading it on an long-haul intercontinental flight for you later today.
My next book, tentatively titled “Fighting Chemophobia”, will be published in late 2017.
I promise that my book “Fighting Chemophobia” will contain the following:
Stories you can share on a first date;
Maths – but just a little;
Chemistry – but not too much;
A deep exploration of chemophobia’s roots;
Tangible solutions to chemophobia;
More stories. Lots of true stories.
This “Fighting Chemophobia” book is for:
Educated people who are interested in a fascinating, growing social phenomenon;
People who want to settle the ‘natural’ vs ‘artificial’ debate;
People who love reading.
To get your hands on a copy, subscribe to this blog for email updates. Just click ‘Follow’ somewhere on this page (its location depends on which device you’re using).
I promise that throughout 2017, you’ll receive teasers, snippets and discarded book fragments via this blog to get you excited.
Inspired by the formula booklets used by VCE Physics and VCE Maths Methods, here’s an 8-page Chemistry formula booklet you can use for your Year 11 and 12 Chemistry assignments. This custom-made booklet is a collection of reliable formulae that I have been using to answer VCE Chemistry questions while teaching and tutoring around Melbourne.
There are 76 formulae on 8 pages. At least 10 of these formulae aren’t in the three main chemistry textbooks. Orders are shipped in A4-sized booklet that resembles the VCAA Data Booklet.
Orders from schools, students and tutors are all welcome. Price includes free international delivery and a 10% voucher for the T-shirt store.
James Kennedy achieved outstanding A-level results in 2006 in Maths, Chemistry, Physics and Biology. Those excellent grades (which equate to an ATAR of 99+) earned him a BA (Hons) degree and a Masters degree in Natural Sciences from the University of Cambridge.
Shortcut formulae were just one of the techniques James used to pass his A-level exams and get into Cambridge. Along with structured revision, revision guides, practice papers and study notes on wall-cards, James used shortcut formulae to save precious time in the examination hall. You can get your own copy of these original shortcut formulae – revised and updated for the 2017-2021 VCE Chemistry course – for just $55 including free international shipping. Click here to get your copy.
This book contains 50 lies taught in the VCE Chemistry course.
These lies include well-meaning simplifications of the truth, mistakes in the textbook, and, in a few extreme cases, blatant falsehoods.
This book isn’t a criticism of the VCE Chemistry course at all. In fact, I just want to highlight the sheer complexity of Chemistry and the need to make sweeping generalisations at every level so it can be comprehensible to our students. This is a legitimate practice called constructivism in pedagogical circles. (Look that up.)
Many of these ‘lies’ taught at VCE level will be debunked by your first-year chemistry lecturers at university.
Here’s a preview of some of the lies mentioned in the book. Check out all 50 by clicking the download link at the bottom of the page.
The content you’re learning now is probably not as true as it seems. Chemistry is a set of models that explain the macro level sometimes at the expense of detail. The more you study Chemistry, the more precise these models become, and they’ll gradually enlighten you with a newfound clarity about the inner workings of our universe. It’s profound.
Rules taught as ‘true’ usually work 90% of the time in this subject. Chemistry has rules, exceptions, exceptions to exceptions, and exceptions to those – you’ll need to peel pack these layers of rules and exceptions like an onion until you reach the core, where you’ll find Physics and Specialist Maths.
Enjoy this book. I hope it emboldens you to question everything you’re told, and encourages you to read beyond the courses you’re taught in school.
Click to download REDOX RULES posters for VCE Chemistry
What’s redox? We never learned that!
Yes, you did. I use the term “redox” to refer to all of the following chapters in Heinemann Chemistry 2, which you will have learned at the end of Term 3 (September).
Chapter 26: Redox (revision of Year 11)
Chapter 27: Galvanic Cells
Chapter 28: Electrolytic Cells
Don’t underestimate redox
The VCAA has consistently used redox to discriminate which schools and students have the self-discipline required to keep studying at the end of the year. Studies show that redox is taught at a time when student motivation is at its minimum: energy levels are low, emotions are high, and graduation is just over the horizon. Many schools and students gloss over these topics because they’re running out of time, any many students think they’ve grasped the topic – when they’ve actually grasped misconceptions instead.
Here are some popular redox lies (misconceptions)
LIE #1: The polarities switch during recharge Nope. The polarities never switch. It’s the labels of ‘anode’ and ‘cathode’ that switch because the electrons are flowing the other way through the external circuit. Polarity is permanent.
LIE #2: Hydrogen fuel cells don’t emit any greenhouse gases Wrong. They emit H2O, which is a powerful greenhouse gas. If you don’t believe that the VCAA can be this pedantic, think again. Read their 2015 Examiners Report here.
LIE #3: Each mole of electrons forms 1 mol Ag, 2 mol Cu or 3 mol Al in a cell Wrong again. If you look at the half-equations, you’ll see that each mole of electrons actually forms 1 mol Ag, 1⁄2 mol Cu or 1⁄3 mol Al. That’s why I teach “1, 1⁄2 and 1⁄3 moles” instead of the typical “1, 2, 3 moles” rule.
LIE #4: Temperature increases the rate of reaction in electroplating
Wrong! Remember that Faraday’s first law states that m ∝ Q. Because Q = I×t, only those two things – current and time – can affect the mass deposited at the cathode.
LIE #5: Electrons always leave the anode and go towards the cathode Wrong again. Electrons go RACO: to see what that means, download the posters above. This question appears in recent versions of Chemistry Checkpoints. Give it a try.
LIE #6: The cathode is always positive Ask your teacher.
LIE #7: Ions flow one way in the salt bridge
Nope. Anions always migrate to the anode; and cations always migrate to the cathode.
LIE #8: KOHES always works for balancing half-equations
KOHES only works for cells with acidic electrolytes. For cells with alkaline electrolytes, which sometimes appear in VCAA papers despite not being in the study design (see page 46 here), you’ll need to use KOHES(OH). Here’s KOHES(OH) explained:
Do KOHES as normal
Add the same number of OH–(aq) ions to each side of the half-equation to balance out the H+(aq)
Cancel and simplify. Remember that H+(aq) + OH–(aq) makes H2O(l). Remember also to cancel out any remaining H2O(l).
LIE #9: I can balance an unbalanced redox equation by putting numbers in the equation Don’t be fooled by this one! The ONLY way to balance an unbalanced redox equation successfully is to do the following:
Separate it into two half equations
Balance them using KOHES or KOHES(OH) as appropriate
Multiply them and recombine
Cancel and simplify
That’s a lot of work but it’s the only way to do it successfully. If you try to ‘cheat’ by just writing numbers (molar coefficients) in front of the reactants and products, you’ll find that the charges don’t add up, and you’ll get zero marks for the question.
LIE #10: I can break up polyatomic ions to make balancing half-equations easier
Nope! You’re only allowed to separate aqueous species in a half equation or an ionic equation. Because the Mn and O are actually bonded together in a polyatomic ion, you’ll need to write this:
If in doubt, keep it intact and it’ll cancel out by the end if it’s a spectator ion.
LIE #11: The two reactants that are closest together on the electrochemical series react Not always true. Use SOC SRA instead, which is explained in the posters above. Still struggling? Ask your teacher or tutor for help.
LIE #12: Oxidants are all on the top of the electrochemical series They’re actually on the left, and all the reductants can be found on the right side of each half equation in the electrochemical series. There is no top/bottom divide on the electrochemical series: only a left/right divide of oxidants/reductants.
Decorate your school/bedroom/hallway
Surround yourselves with truthful redox revision using these 17 free Redox posters. I’ve had these up around the whiteboard for a few weeks now – they’re a constant reminder to students that redox has many ideas that are always true.
One more tip: print and laminate an electrochemical series (available here) so you can annotate it during dozens of practice dozens without wasting paper. Good luck!
Today, we’re going to answer the following question:
When 200 grams of ice is added to a bucket containing 1.00 litre of hot water, what’s the final temperature of the water?
To answer the question, we’re going to need to make some assumptions. We’ll take 1.000 litre of pure water at 80.00°C and add 200.0 g of ice (at -10.00°C) to it. What’s the final temperature of the water?
Part 1: Heat transfer method
The following equation can calculate the temperature at thermal equilibrium of any number of objects in thermal contact.
I love this equation because it’s several lines of maths shorter than the version taught in school. With this equation, you don’t even need to convert the temperatures into kelvin. Celsius works just fine.
Let’s set up the equation so that the addition series contains the variables in the question.
Now, let’s substitute the gives values into the equation. The specific heat capacity of water is 4200 J kg-1 K-1, and that of ice is 2100 J kg-1 K-1.
Great! Adding 200.0 g of ice to 1.000 L of water decreases the temperature from 80.00°C to 71.80°C.
But we’ve forgotten something. The ice will melt as soon as it hits the hot water. Since melting is an endothermic process, heat energy from the water will actually be absorbed, thus reducing the final temperature even further.
Part 2: Let’s take into account the fact that the ice melts!
Remember our formula from part 1.
The amount of energy required to melt ice can be calculated using the latent heat equation:
Removing that amount of heat energy from the system results in the following equation:
Great! Now, we’ve calculated that the final temperature of the water would be 57.36°C after the addition of the ice. That’s equal to 330.5 kelvin, which will be useful later.
However, we’ve forgotten to take something else into account: how much heat will be lost as radiation from the surface of the bucket?
Part 3: What’s the rate of heat loss from the bucket by radiation?
The rate of heat lost by radiation can be calculated by using the Stefan-Boltzmann equation, below.
P is the rate at which heat energy is radiated from the surface of the bucket in watts. Emissivity, e, of water is 0.95, and the surface area, A, should be around 0.0707 m2 for a one-litre bucket. Calculation of A is shown below. Assuming that the radius of the surface of the bucket is 6cm:
Plugging that value into the equation, we can find P. We’ll assume that the experiment is being conducted at room temperature and the temperature of the surroundings is 20.00°C (29.03 K).
This means that 2.928 joules of energy are emitted from the surface of the bucket every second. Ten minutes later, the bucket would have lost 1756.8 joules of energy due to radiation from the surface. But what about emission of radiation from the sides of the bucket?
Let’s say that our bucket is made from highly polished aluminium (which has emissivity 0.035) and it holds exactly 1.2 litres of water. We need to calculate the dimensions of the bucket.
Assuming it has straight sides (i.e. it’s a cylinder), the bucket had volume equal to the following formula:
The surface area of our bucket (excluding the open surface at the top) is:
The rate of energy radiation from the sides would therefore be:
It’s interesting to note how very little radiation is emitted from the shiny aluminium bucket, while lots more radiation is emitted from the surface of the water. This is because relatively ‘dark’ water has a much higher emissivity than shiny aluminium. Total emission from the bucket is therefore:
After ten minutes, the bucket would have lost the following amount of energy:
Let’s factor this amount of energy loss into our final temperature equation.
Not much energy is lost via radiation! Finally, let’s find the peak wavelength of the radiation emitted by the object using Wien’s law.
Part 4: What’s the wavelength of the radiation being emitted by the bucket?
Here’s Wien’s law from Unit 1 Physics…
The radiation emitted from the resulting bucket of water lies firmly in the infra-red part of the electromagnetic spectrum. The bucket would be clearly visible on an infra-red camera!
Next week, we’ll begin a new a Chemistry-themed project called Periodic Table Smoothie. More next week.
Sleep is an essential part of our development and wellbeing. It is important for learning and memory, emotions and behaviours, and our health more generally. Yet the total amount of sleep that children and adolescents are getting is continuing to decrease. Why?
Although there are potentially many reasons behind this trend, it is emerging that screen time – by way of watching television or using computers, mobile phones and other electronic mobile devices – may be having a large and negative impact on children’s sleep.
It has also been suggested that longer screen times may be affecting sleep by reducing the time spent doing other activities – such as exercise – that may be beneficial for sleep and sleep regulation.
Screen time in the hours directly prior to sleep is problematic in a number of ways other than just displacing the bed and sleep times of children and adolescents. The content of the screen time, as well as the light that these devices emit, may also be responsible for poorer sleep.
The content, or what we are actually engaging with on the screen, can be detrimental to sleep. For example, exciting video games, dramatic or scary television shows, or even stimulating phone conversations can engage the brain and lead to the release of hormones such as adrenaline. This can in turn make it more difficult to fall asleep or maintain sleep.
The number of devices and amount of screen time children and adolescents are exposed to is continually increasing. Given these early associations with reduced sleep quality, and the importance of sleep in healthy development and ageing, this is an issue that is not likely to go away any time soon.
Sleep should be made a priority, and we can combat this growing problem in a number of ways.
The leading internet blocker, Stop Procrastinating, has announced that 64% of US students have cited online distractions such as social media as a hindrance to their productivity. Facebook, Twitter, Snapchat, shopping websites and YouTube were among the sites that students found the most distracting.
Fear of Missing Out (FOMO)
Nearly all of the students who responded in the survey referred to a ‘fear of missing out’ (FOMO), which is the anxiety that people experience when they believe that important events are happening without them. The anxiety arises from a perceived decrease in ‘popularity’ if they’re not up-to-date with the latest happenings in their social circle. Teenagers are particularly susceptible to FOMO, and 24-hour social media feeds such as Facebook and Twitter are exacerbating the problem. Students are constantly checking their social media feeds (sometimes a few hundred times per day) in order to keep up with the latest drivel happenings.
Interestingly, first year university students were the most affected. It’s possible that in first year (sometimes called “freshman year”), people’s social circles haven’t quite cemented since the upheaval of leaving high school. People are therefore more anxious and fear missing out on new friendships and events… so they gravitate towards social media.
Almost half students surveyed admitted to losing an hour each day to social media. Common Sense Media estimates the real figure (including traditional media such as TV) is more like 9 hours per day. That’s a lot of screen time, and it’s affecting students’ social lives, their grades and their sleep.
Over half of the respondents said they’d been stopped from writing an essay because they felt compelled to check social media at some point. Any issue that’s stopping half of our students from writing essays (or concentrating for any extended period of time) needs to be addressed urgently.
This problem needs to be addressed urgently
The level of distraction today is unprecedented. We all carry televisions and music players in our pockets. I got in touch with Tim Rollins, the director of Stop Procrastinating, who said:
“We have made Stop Procrastinating free today in order help students to beat their Internet distractions and boost their performance in their studies. The Internet, social media, emails are pervasive and eating into our quality time. We need urgently to put ourselves back in control.” – Tim Rollins
Software is one of the tools that can help students get the lasting willpower they need to overcome FOMO and get back into studying. Here are my tips for eliminating distractions while studying.
Study without music. All the research says it doesn’t help.
Don’t eat and study at the same time.
Drink only water while you’re studying.
Sit upright while studying: don’t study laying in bed or leaning back on the couch.
Have a goal for each study session. Write it down and work until you’ve completed it (e.g. make notes on all 6 types of acid/base chemical reactions with examples)
Study in a location that you never use for relaxation… the library is a great choice. Most students can’t study in their bedroom because they usually relax there.
Limit the number of Facebook friends to 30. Delete all the others: I understand this takes some courage, but you probably don’t know them anyway! Their unimportant updates distract you from studying.
Stop Procrastinating is an Internet blocking and productivity application compatible with OS X and Windows. It allows users the option to block the Internet for a period of time in three ways, depending on how much self-discipline they have.
It’s been two years since I posted the All-Natural Banana. Motivation behind this poster was to dispel the myth that “natural = good” and “artificial = bad”. It’s been a very successful project. It’s spawned 11 more “Ingredients” posters, a successful clothing line, and has sold thousands of print copies worldwide via this website.
Demonstrate electrolysis with an electrolytic cell in a petri dish.
1 × Large petri dish
1 × DC Power pack
~50 mL Distilled water dH2O(l)
~3 g potassium nitrate powder KNO3(s)
2 × Graphite electrodes
2 × Wires with crocodile clips
1 × Clamp and stand
1 × Very strong static magnet
1 × Roll of sticky tape (any type)
~10 drops of universal indicator
~50 mL dilute HNO3(aq)
~50 mL dilute KOH(aq)
1 × Spatula
Place petri dish on clean, light-coloured bench and add distilled water until it is two thirds full
Add ~10 drops of universal indicator and observe the colour. Q: What pH is the distilled water? (You’ll be surprised!) Q: Why is/isn’t the colour green?
Add ~3 g of potassium nitrate to the petri dish and stir using a spatula until completely dissolved
Adjust the pH of the distilled water carefully using the nitric acid and potassium hydroxide as required. Try to make the universal indicator colour green (as pictured) ~pH 7
Attach one electrode to each of two wires using crocodile clips
Dip each graphite electrode into the green solution at opposite sides of the petri dish. Hold these electrodes (and wires) in position by in position by sticky-taping each wire to the surface of the workbench
Demonstrate the strength of the magnet by attaching it to the clamp. Carefully, clamp the magnet into the clamp and position the magnet 2 mm above the surface of the green solution
Ensuring the power is turned off, very carefully, attach the wires to the DC power pack according to the manufacturer’s instructions
Turn the voltage to zero (or very low) and turn on the power pack
Turn the voltage up slowly (12 volts worked well) and observe any changes you might see in the Kennedy Rainbow Cell
Turn off the power pack and stir the solution. Explain why the colour goes back to being green. (If it’s not green, explain that, too!)
Turn the magnet upside-down (TURN OFF THE POWER FIRST)
Reverse the polarity of the wires
Use AC current instead of DC
Use different indicators
Why would using NaCl(aq) be dangerous in this cell?
Make your own risk assessment before carrying out this experiment
The strong magnet is capable of attracting both wires to itself. Don’t be touching the exposed parts of the crocodile clips when this happens. If this does happen, immediately turn off the power pack and fix the problem. Secure the wires with more tape. Don’t touch the electrodes while the Cell is operating.
Don’t use chloride salts or hydrochloric acid in this experiment. The voltages involved can cause the production of toxic chlorine gas if sodium chloride is used. Use nitric acid and potassium nitrate instead.
Make sure the wires don’t touch each other.
Again, make your own risk assessment before carrying out this experiment
This cell is potentially dangerous. I accept no responsibility for and loss, damage or injury caused by the operation of a Kennedy Rainbow Cell. If you’re under 18, always get adult permission before you make this type of cell.
The groups credited for creating them – in Japan, Russia and the US – have spent several years gathering enough evidence to convince experts from Iupac and its physics equivalent, the International Union of Pure and Applied Physics, of the elements’ existence. All four are highly unstable superheavy metals that exist for only a fraction of a second. They are made by bombarding heavy metal targets with beams of ions, and can usually only be detected by measuring the radiation and other nuclides produced as they decay.
Solubility rules are among the most important things you’ll need to memorise in your VCE Chemistry studies. There are two main ways to get this done: either learn a set of rules or memorise all the compounds you need by themselves. I use a mixture of these two methods to figure out whether a compound dissolves in water or not.
Test your students (or yourselves) with a set of Soluble or Not? flashcards. Each flashcard has a commonly-used compound on the front (e.g. Zn(OH)2) and the word SOLUBLE or NOT on the back.
Front of each card
Back of each card
There are three ways to use these cards.
1. Name the compound.
Present the cards to the student white side up. The student should state the full name including Roman numerals (e.g. iron(III) oxide) as quickly and accurately as possible.
2. State the formula.
Present the cards red/green side up. The student should state the chemical formula of each compound accurately. This step also serves as a primer for the next stage, which requires students to know whether each of these compounds is soluble. The solutions are visible during this step of the game.
3. Soluble or Not?
Present the cards white-side up again. Ask the student to separate the cards into two piles (“SOLUBLE” and “NOT”) without turning them over. At the end, collect all the cards, turn them all over and review the ones that were incorrect. Repeat weekly until the student can get all of them right.
This is where you might want to buy your own set of cards. I’ve hand-picked compounds that come up frequently in VCE examinations from units 1-4, and these will help you focus your learning.
“Why bother reading?” is a question I’m asked occasionally by students, and “reading makes you smarter” is my standard response. This week, I want to expand on this fact and give some evidence for reading being a major contributor not only to academic success, but to success in many other aspects of life as well.
Reading improves your IQ and EQ
Firstly, there’s convincing evidence by Mar et al., (2009) that people who read fiction have greater ability to understand others’ emotions, emphasise with them and view the world from their perspective. In other words, reading increases your emotional quotient (EQ).
Second, there’s convincing evidence that reading increases your vocabulary. Cunningham & Stanovich (2001) penned an excellent analysis that includes evidence from many other studies that a person’s vocabulary is increased fastest by reading, particularly reading books outside of school hours, than by learning lists of vocabulary on their own.
Improving your EQ has obvious benefits. But what are the advantages of increasing your vocabulary? Increased vocabulary has been shown to be linked with increased intelligence and socioeconomic status. Even if the link is correlative and not causative, people will still benefit from the perceived intelligence that an increased vocabulary brings about.
Furthermore, Olson, D. R. (1986) writes:
It is easy to show that sensitivity to the subtleties of language are crucial to some undertakings. A person who does not clearly see the difference between an expression of intention and a promise or between a mistake and an accident, or between a falsehood and a lie, should avoid a legal career or, for that matter, a theological one.
It has also been widely argued in the literature that reading can increase vocabulary faster than verbal interactions because our written vocabulary is so much more diverse than our spoken vocabulary.
What type of reading should I be doing?
Deep reading is the most effective way to increase your IQ and EQ.
Deep reading involves:
decreased physical activity while reading
zero distraction (or immunity to distraction: being ‘in the zone’)
reading for extensive periods of time: many hours in one sitting
processing the things you read in a meta-cognitive way, e.g. writing book reviews or making notes as you read
Deep reading is vigorous exercise from the brain. It increases our capacity for empathy in real life. Deep reading is slow, immersive, rich in sensory detail and emotional and moral complexity, and is very different from the kind of reading we do on the internet or even in school. Deep reading is a distinctive experience, different in kind from the mere decoding of words. Victor Nell reported in 1988 that deep readers read their favourite pages more slowly than average, and that deep reading is usually accompanied by a significant decrease in physiological activity. He even noted that deep reading sets the reader into a psychological state akin to a hypnotic trance.
“…deep reading sets the reader into a psychological state akin to a hypnotic trance.” – Victor Nell (1988)
Can I use an iPad or an e-reader?
Not for deep reading, no. Use an e-reader or an iPad for reading magazines and news articles only. Not only are electronic devices prone to distracting you (under the ruse of ‘multitasking’), but studies have shown that readers who read books on electronic devices:
leave lower reviews on Amazon.com than for hardback versions of the same book
While reading can be done on electronic devices, deep reading needs to be done from paper. Not only are printed books free of popup notifications and advertisements, they also kinder on your eyes (because they’re not backlit) and lend themselves better to being highlighted and annotated in the margins if required.
Here’s a flowchart derived from Cunningham & Stanovich that explains why some people hate reading. Their premise is that people who hate reading have been introduced to books that are too difficult so the excessive focus on the meaning of individual words distracts people from the meaning of paragraphs or chapters as a whole.
It’s therefore important to choose books of an appropriate reading level.
So what should I read (or, ‘deep read’)?
Choose a genre that matches your interests and a medium that matches your reading level. The material you read should be not too easy and not too difficult. Here’s a rough guide to the difficulty level of different types of media.
Occasionally, try to expand your horizons by challenging yourself to read something you wouldn’t normally read. Here are some great ways to read outside your comfort zone:
swap books with a friend;
get books recommended to you by a teacher, tutor or a family member;
participate in a book club, in which you read a new book each month or fortnight.
How much should I read each day?
Aim to read 3,300,000 words per year. That equates to about one book per week, which puts you above 95% of the adult population.
In 2012, when I realised I wasn’t reading enough, I decided to read a book every two days. I posted all the reviews online as a way of holding myself accountable to reading them thoroughly and deeply. Reading this much was difficult and time-consuming at first, but, just like sports, I become faster and more proficient as I read more books.
Read one book per week and review it online to keep yourself accountable.
Get involved in deep reading by reading one book per week and posting the reviews online. Here’s your new reading process for the new year.