Lithium: a rare earth metal that is lighter than air?


Keith S. Taber


It was purely by accident that I had the radio on when I heard it claimed that

The actual phrase that caught my attentions was

"the lightest metal on earth, lighter in fact than air, lithium".

This seemed bizarre, to say the least.

I went to the BBC website page for the programme concerned (an episode of a series called 'The Scramble for Rare Earths'), where it was acknowledged that a mistake had been made:

"Correction: this episode incorrectly states that lithium is lighter than air. Lithium has a lower atomic mass than oxygen or nitrogen."

So, someone at the BBC had spotted the mistake, or it had already been pointed out to them.

But I thought the correction was interesting in itself, as it made perfect sense to someone who would have the subject knowledge to have noticed the error and appreciated how it came about. I was less sure it would explain much to someone who did not already appreciate the ambiguity of the labels we give to both substances and also to the nanoscopic particles from which the are composed. More on that below, but first there is another clarification needed.

The bearable lightness of beings

Lightness strictly contrasts with heaviness, and so is about weight. Thus the 'old chestnut'1:

which is heavier: a tonne of lead or a tonne of feathers?

Of course, by definition, the mass of a tonne of anything is fixed – so a tonne of feathers has the same mass (and so, in the same gravitational field, the same weight) as a tonne of lead, even if our instinct is that feathers are lighter.

So, really this is about density. When someone (sorry, Misha Glenny) makes the reference:

the lightest metal on earth, lighter in fact than air, lithium

We might respond in various ways:

  1. this is a meaningless comparison as without knowing how much of each we are comparing it is not possible to draw any conclusion (a great deal of air would be heavier than a tiny amount of lithium);
  2. to make sense of this we must assume we are considering the same amount of each; or
  3. yes, that seems reasonable: the lithium metal on earth weighs less than the air.

Option 1 is clearly a pedantic response – 'we will not assume something you do not tell us: it is not for us to add necessary information you have omitted'. Now this would be my response, but then I know I have a mind which tends to such pedantry. I would like to think this is due to my scientific training but actually think it predates that. Perhaps I am just a pedantic person.

Option 3 follows a line of argument that as we have not been told how much is being considered, then the only admissible assumption from the claim is this refers to the earth ("metal on earth"). Lithium is a reactive element (which is why it is stored under oil to avoid oxygen reaching the surface – see the image below), not found native, so any lithium metal on earth is the result of deliberate processing – and, surely, there is much less weight of lithium metal here than the weight of the atmosphere. (However, invoking the earth as a whole complicates the mass:weight relationship, so we would need to specify where we are doing the weighing – say at the earth's surface beneath the atmosphere.) I suspect most people would immediately dismiss this as not being the intended meaning.

The sensible option?

Option 2 would surely be how most people would interpret "lighter than"given the context of the claim. As long as we agree on what we mean by 'the same amount', we have no problem. We have already considered one option which clearly does not work: same amount = same mass.

In chemistry, amount of substance is measured in moles. One mole of lithium weighs about 7 g. But we only apply moles to collections of what we take as identical entities. Lithium metal is comprised of lithium atoms2, and although these atoms are not all identical (natural lithium has a small proportion of 6Li with only three nuclear neutrons mixed with the majority 7Li) they can be assumed near enough so for most purposes.

Air, however, is a mixture of different substances: mainly nitrogen, oxygen and argon, but also including many others in smaller amounts. And its composition is not fixed. In particular, the water vapour levels change a good deal; but also CO2 levels (say, over a forest as opposed to a dessert, even ignoring anthropogenic inputs due to human activity); SO2 levels being higher near active volcanoes; higher nitrogen oxides and ozone levels from car emissions in built up areas; carbon disulphide levels from algae being higher over some sea areas, etc, etc.

But dry air is mostly nitrogen and oxygen, and a mole of nitrogen weighs about 28g and a mole of oxygen about 32g, so a gas mixture which is nearly all nitrogen and oxygen and which contains 'a cumulative mole'* of these gases (say about 0.78 moles of nitrogen and 0.21 moles of oxygen, and a small amount of other atmospheric material) will weigh more than our 7g of lithium.

* But we had to do some violence there to the proper use of the mole concept.

The sharp-eyed will also have noticed that the molar masses of the substances oxygen and nitrogen were based on molecular masses – for the good reason that in the air these substances exist as diatomic molecules. That is, while it is true that "lithium has a lower atomic mass than oxygen or nitrogen" that cannot be a full explanation as atomic mass is not the most relevant factor for these gases. 3

So, 'same amount' cannot be weight, and it is not moles, but rather can sensibly be volume. Volume for volume, a denser material is heavier than a rarer (less dense) one. Sensibly, then, the claim being made in the radio programme/podcast can be understood to be that lithium is less dense than air – thus explaining all those lithium balloons we see floating around.4


photograph of lump of lithium floating in oil.

A sample of the metal lithium in oil (source: wikimedia. This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.)

The metal is floating in the oil, showing it has a lower density (is 'lighter') than the oil. However, the metal is clearly not 'lighter than' air.


The chemist's triplet

Now I have rather made a lot of a single broadcast error, that it seems had already been acknowledged (though I doubt more than a very small proportion of radio listeners systematically check out webpages to find out if the programmes they listen to contain any acknowledged errors). But I think what happened here is symptomatic of a core issue in chemistry, and the teaching of chemistry.

This refers to something first widely highlighted by the Glasgow based scholar Prof. Alex Johnstone in 1982, and known as his triangle. Chemistry deals with substances which are handled at bulk scale in the laboratory and explains the proprieties of these substances in terms of models concerning theoretical entities at the nanometre scale: electrons, bonds, ions, molecules, atoms and so forth. Johnstone referred to the 'microscopic' level as opposed to the 'macroscopic level', and so this term is widely used, but a better term might be submicroscopic (or nanoscopic, cf. the nanometre) as single ions and discrete molecules are not even close to being visible under any optical microscope. 5

Further, chemistry has its specialised symbolic language, such that, for example, a chemical reaction would commonly be represented in terms of a reaction equation using chemical formulae. The expert chemist or science teacher moves effortlessly around the macroscopic/microscopic/symbolic apices of this chemist's triangle, but Johnstone strongly argued that classroom presentations that readily moved back and forth between bench phenomena, equations, and talk of molecules, would overwhelm the working memory of the novice learner. (If you are not familiar with the critical notion of working memory, perhaps check out 'how fat is your memory?')


cover of RSC book Johnstone Triangle: The Key to Understanding Chemistry

The Johnstone Triangle

The Key to Understanding Chemistry


The idea of this 'chemist's triplet' (as it is sometimes labelled, borrowing a term from spectroscopy) has been considered the most important factor specific to chemistry pedagogy, and indeed there is at least one whole book on the topic (Reid, 2021).

Johnstone was right to alert science teachers to this issue, although an authentic chemistry education does have to work to move learners to a position where they can interpret and move across the triplet. Chemistry students need to learn to associate phenomena (e.g., burning) with both technical descriptions (e.g., combustion, oxidation) and with molecular level models of what is going on in terms of bond breaking and so forth (Taber, 2013). But learners will need much support and practice, and to be given sufficient time, to develop competence in this ability.



Perhaps a trivial example is moving from the everyday description that, say, mercury is 'heavy' (with only an implied notion of how much mercury we are talking about) to the more technical reference to density, and an explanation based on the micro-structure of mercury in terms of ions (and conduction electrons) in the condensed state.


Figure showing a triangle of experiential level, theoretical-descriptive and theoretical-explanatory levels.
The chemist's triplet (Taber, 2013)

Useful and misleading ambiguity

Part of the challenge for teachers (and so learners) is how key terms can mean different things according to context. So, the labels 'mercury' and 'Hg' can refer to an element in abstract, but they also refer to some of the substance mercury (a macrosopic sample of the element) and to an individual atom of mercury. A chemical equation (such as 2H2 + O2 ⇾ 2H2O) can refer to bulk quantities of substances reacting, but also to individual molecules within the theoretical models used to explain what is going during the reaction.

Often during a chemical explanation the same label ('mercury') or equation (2H2 + O2 ⇾ 2H2O) will be referred to several times, as the focus shifts from macroscopic substance to submicroscopic entities, and back again. This adds to the learning demand, but can also be confusing unless a teacher is very explicit at each point about which is being signified. An ambiguity which can be useful for the fluent, can also be confusing and frustrating for the novice (Taber, 2009).

So, in moving from considering atoms (where lithium has less mass than nitrogen) to substances (where under standard conditions lithium is much more dense than nitrogen) the meanings of 'lithium' and 'nitrogen' change – and perhaps that is what confused journalist Misha Glenny or whoever prepared his script. The experienced science teacher may find this a surprising basic error in a programme from an elite broadcaster like the BBC, but perhaps this is a useful reminder just how easily learners in introductory classes can be confused by the ambiguity reflected in the 'chemist's triplet'.

Read more about this macro-micro confusion

Rare earths – a double misnomer

The radio programme claiming lighter-than-air lithium was part of a short series on 'The Scramble for Rare Earths'. Now 'rare earths' refers to the elements also known as the lanthanides, part of the 'f-block' in the periodic table.

The term 'earth' is also found in the common name of the group of metals, including calcium and magnesium, known as the 'alkaline earths'. 'Earths' is an anachronistic reference to materials such as oxides which were not actually elements. So, the term alkaline earths is misleading as these elements are not 'earths' but the label has become established. (Who would be a chemistry student?)

The 'rare earths' are not earths either, but metallic elements. They are also not all especially rare. They were not initially readily recognised and characterised as different rare earth elements often have similar chemical properties and they occur in the same ores, and so historically they proved difficult to separate and identify. This label of 'rare earth' is then also something of a historical hang-over: although these elements are widely dispersed in the earth's crust so although not actually rare, they are seldom found in highly concentrated sources from which they can be readily extracted.

Rare earths do not seem to be well understood by the lay-person: quite a few websites claim that "quinine contains rare earth compounds" (see 'Would you like some rare earths with that?') As quinine (an antimalarial compound often taken as a 'tonic') is a single chemical substance, it clearly does not contain other compounds: but, in any case, its formula is C20H24N2O2 so its elemental composition is just of hydrogen, carbon, nitrogen and oxygen. Thus the repeated claim about rare earths in quinine seems curious.

The paradox of 'The Scramble for Rare Earths'

But then the BBC's blurb for the radio programme I came across, an episode of 'The Scramble for Rare Earths' called 'The Hidden Paradox', tells us:

"Misha Glenny explores the world of rare earth metals. Reducing CO2 emissions requires critical raw materials like lithium, cobalt and nickel but mining and processing them can pose a serious threat to the environment. Can we solve the paradox?"

Presumably the paradox being that Misha Glenny explores the world of rare earth metals with reference to the alkali metal lithium, and transition elements cobalt and nickel: none of which are rare earths. Perhaps he found the rare earths too rare to include? Perhaps I need to listen to the rest of the programme.


Work cited:

Notes

1 This is an idiom – a phrase which has currency in the language, and has come by convention to have a particular meaning; but where that sense is not clear from the literal meanings of the individual words. An 'old chestnut' is (when it is not a chestnut that is old) something which has been repeated so often it is familiar and loses any impact.

I suspect most readers will have met this question before (or a variation on it) and will not be caught out to suggest the feathers weigh less than the lead.

Read about idioms in science discourse


2 Strictly, solid lithium metal contains an array of Li+ ions in a field of delocalised electrons. No particular electron is associated with any specific lithium ion – they are in molecular orbitals and – being delocalised – do not stay in the same place. So a mole of lithium is a mole of Li+ ions with a mole of (collectively, but not individually) associated electrons. This is just one complication that must make chemistry difficult for learners.


3 We say a mole of lithium is 7g, although this counts the individual 'atoms' (see note 2) even in the solid state where a single metallic crystal could be seen to be more akin to a single molecule. Of course, a mole of lithium crystals would have a mass MUCH more than 7g. Arguably, it is somewhat arbitrary how we define a mole of metallic lithium (and a mole of an ionic solid even more so) compared with a mole of simple molecular substances such as methane or carbon dioxide – but the convention is well established. This is a formalism that could be different – but not if you want to score the marks in a chemistry examination.


4 If lithium was heated to give off vapour, then that vapour would be less dense than air. However lithium is highly reactive and the vapour can only be kept stable in a vacuum or an inert atmosphere (and would only remain a vapour in an atmosphere at a high enough temperature). In the earth's atmosphere any slight leakage from a balloon would likely quickly lead to an explosive failure. Perhaps there is a planet somewhere with a hot enough argon atmosphere where lithium filled balloons could in principle be safely used if a suitable inert material could be found to make the balloon itself – but I doubt this would ever be a preferred option.


5 Arguably, a pure single crystal diamond could be considered a molecule, but that is not what we normally mean by a molecule. Again the choice of how to label different entities is somewhat arbitrary (in the sense that different decisions could rationally have been reached), and learners have to acquire the canonical, historically contingent, labels.


Would you like some rare earths with that?

A chemically illiterate internet meme


Keith S. Taber


The challenge of popular science writing

I often enjoy reading popular accounts of science topics, but sometimes one comes across statements that are vague or dubious or confusing – or simply wrong. Some of this reflects a basic challenge that authors of popular science share with science teachers and other science communicators: scientific ideas are often complex, subtle and abstract. Doing them justice requires detailed text and technical terminology. Understanding them often depends upon already having a good grasp of underpinning concepts. That is fine in a formal report for other scientists, but is not of any value to a non-specialist audience.

So, the author has to simplify, and perhaps round off some of the irregular detail; and to find ways to engage readers by using language and examples that will make sense to them. That is, finding ways to 'make the unfamiliar familiar'.

Read about making the unfamiliar familiar in teaching

I am sure that often the passages in popular science books that I as a scientist 1 get grumpy about are well motivated, and, whilst strictly inaccurate, reflect a compromise between getting the science perfect and making it accessible and engaging for the wider readership. Sometimes, however, one does get the impression that the author has not fully grasped the science they are writing about.


"Lucy Jane Santos is the Executive Secretary of the British Society for the History of Science…"


Public engagement with radium

I very much enjoyed reading a book, 'Half lives', by the historian of science Lucy Jane Santos, about how in the decades after its discovery by Pierre and Marie Curie, radium was the subject of wide public interest and engagement. One of the intriguing observations about this newly discovered element was that it appeared to glow in the dark. We now know that actually the glow comes from nitrogen in the air, as radium is radioactive and emissions by radium 'excite' (into a higher energy state) nitrogen molecules, which then emit visible light as they return ('relax') to their 'ground' state. This production of light without heating (a phenomenon generally called luminescence), when it is due to exposure to radioactivity, is known as radioluminescence.

Today, many people are very wary of radioactivity – with good reason of course – but Santos describes how at one time radium was used (or at least claimed as an ingredient) in all kinds of patent medicines and spa treatments and cosmetics (and even golf balls). This was a fascinating (and sometimes shocking) story.

What substance(s) can you find in quinine?

I did find a few things to quibble over – although across a whole book it was, only, a few. However, one statement that immediately stood out as dodgy science was the claim that quinine contained phospor:

"Quinine contains phosphor, a substance that luminesces when exposed to certain wavelengths of light…"

Santos, 2020

This may seem an unremarkable statement to a lay person, but to a scientist this is nonsensical. Quinine is a chemical compound (of carbon, hydrogen, nitrogen and oxygen), that is – a single substance. A single substance cannot contain another substance – any more than say, a single year can contain other years. An impure sample of a substance will contain other substances (it is in effect a mixture of substances), but quinine itself is, by definition, just quinine.


Molecular structure of the chemical compound quinine (C20H24N2O2) – a pure sample of quinine would contain only (a great many copies of) this molecule.

Note – no phosphorus, and no rare earth metal atoms.

(Image source: Wikimedia)


Confusing terminology

The term 'phosphor' refers to a luminescent material – one that will glow after it has been exposed to radiation (often this will be ultraviolet) or otherwise excited. The term is usually applied to solid materials, such as those used to produce an image in television and monitor screens.

The term derives by reference to the element phosphorus which is a luminescent substance that was accordingly itself given a name meaning 'light-bearing'. The term phosphorescent was used to describe substances that continue to glow for a time after irradiation with electromagnet radiation ceases. But it is now known that phosphorus itself is not phosphorescent, but rather its glow is due to chemiluminescence – there is a chemical reaction between the element and oxygen in the air which leads to light being emitted.

The widely used term phosphor, then, reflects an outdated, historical, description of a property of phosphorus; and does not mean that phosphors contain, or are compounds of, phosphorus. There is clearly some scope for confusion of terms here. 2


termmeaning
luminescencethe emission of light by a cold object (in contrast to incandescence)
chemiluminescencea form of luminescence due to a chemical reaction
– – bioluminescencea form of chemiluminescence that occurs in living organisms
electroluminescencea form of luminescence produced by passing electrical current through some materials
photoluminescencea form of luminescence due to irradiation by electromagnetic radiation, such as ultraviolet
– – fluorescence a type of photoluminescence that only occurs whilst the object is being excited (e.g., by exposure to ultraviolet)
– – phosphorescencea type of photoluminescence that continues for some time after the object has been being excited (e.g., by exposure to ultraviolet)
radioluminescencea form of luminescence due to a material being exposed to ionising radiation (e.g., 𝛂 radiation)
sonoluminescencea form of luminescence due to a material being exposed to sound
phosphora material that exhibits luminescence
phosphorusa chemical element that exhibits chemiluminescence (when exposed to air)
There is a range of terms relating to luminescence. Here are some of those terms.


Some central ideas about luminescence (represented on a concept map)

A traditional medicine

Quinine, a substance extracted from the bark of several species of Cinchona, has long been used for medicinal purposes (e.g., by the Quechua people of the Americas 3), as it is a mild antipyretic and analgesic. It is an example of a class of compounds produced by plants known as an alkaloids. Plant alkaloids are bitter, and it is thought their presence deters animals from eating the plant. We might say that Quechua pain medication is a bitter pill to swallow.


Modern science has often adopted and developed technologies that had long been part of the 'traditional ecological knowledge' of indigenous groups – such as making extracts from Cinchona bark to use as medicines.

Sadly, the original discovers and owners of such technologies have not always been properly recognised when such technologies have been acquired, transferred elsewhere, and reported. 3

(Image by GOKALP ISCAN from Pixabay)


Quinine is an ingredient of tonic water (and bitter lemon drink) added because of its bitter taste.

(Why deliberately make a drink bitter? Quinine has anti-malarial properties which made it a useful substance to add to drinks in parts of the world where malaria is endemic. People liked the effect!)

Quinine glows when exposed to ultraviolet light. It is luminescent. To be more specific, quinine is photoluminescent. (This is responsible for the notion that someone offered a gin and tonic at a disco should test it under the 'blacklights' to make sure they have not been given pure gin to drink. Although, I am slightly sceptical about whether the kind of people that drink 'G&T's go to the kind of dances that have ultraviolet lighting.)


"I do apologise, I think I might have just splashed a tiny droplet of my tonic water on you"

(Image by Victoria_Watercolor from Pixabay)


It is reasonable to describe quinine as a phosphor in the wider sense of the term – but it does not contain another phosphor substance, any more than, say, iron contains a metallic substance or sulphur contains a yellow substance or sucrose contains a sweet substance or copper a conducting substance. So, a more accurate formulation would have been

"Quinine [is a] phosphor, a substance that luminesces when exposed to certain wavelengths of light…"

or, perhaps better still, simply

"Quinine [is] a substance that luminesces when exposed to certain wavelengths of light…"

Ask the oracle

I was intrigued at why Lucy Jane Santos might have been confused about this, until I did a quick internet search. Then I found a range of sites that claimed that quinine contains phosphors – indeed, often, rare earths are specified.

The rare earths (another unfortunate historic choice of name, as it transpired that they are neither especially rare nor 'earths', i.e., oxides) are a group of metallic elements. They are not as well known as, say, iron, copper, zinc, aluminium or gold, but they have with a wide range of useful applications.


Scandium, the first of the 'rare earth' metals. Probably not what you want in your tonic water.

(Creative Commons Attribution 3.0 Unported License, sourced from https://images-of-elements.com/scandium.php)


If something is repeated enough, does it become true?

Clearly there are not rare earths in quinine. So, the following quotes (from sites accessed on 7th March 2023) proffer misinformation.

"If you want to get a bit more scientific about it…. quinine contains rare earth compounds called phosphors.  These are the substances which glow when they are hit with particular wavelengths of the EM spectrum, including UV light.  Phosphors absorb UV light and then emit it in their own colour, in this case glowing blue light."

https://www.iceandaslice.co.uk/blogs/news/why-does-your-gin-and-tonic-glow-blue-in-ultraviolet-light

This claim is odd, as the previous paragraph explained more canonically: "why does quinine absorb UV light (the invisible component of sunlight that produces sun tans and sunburns!)? It is due to the structure of the quinine molecule, which enables it to take in energy in the form of invisible UV light and immediately radiate some of that same energy in the form of visible blue light." Other compounds cannot be inside a molecule – so this more canonical explanation is not consistent with quinine containing other "substances" which were "rare earth compounds."


"Quinine contains rare earth compounds called phosphors. These substances glow when they are hit with particular wavelengths of the EM spectrum, including UV light. Phosphors absorb UV light and then emit it in their own color [sic, colour]. Thus, the black light's UV radiation is absorbed by the phosphors in the quinine, and then emitted again in the form of glowing blue light."

https://sciencing.com/quinine-fluorescent-5344077.html

The following extract appeared under the subheading "Why is quinine fluorescence?" That reflects a category error as quinine is a substance and fluorescence is a process (and fluorescent the property) – so, presumably this should have read why is quinine fluorescent?

Why Quinine Glows

Quinine contains rare earth compounds called phosphors. … Phosphors absorb UV light and then emit it in their own color [sic, colour]. Thus, the black light's UV radiation is absorbed by the phosphors in the quinine, and then emitted again in the form of glowing blue light.

https://allfamousbirthday.com/faqs/does-tonic-water-make-things-glow-in-the-dark/

"Want to know one more fun fact about quinine? It glows.
Rare Earth compounds called phosphors in quinine glow under certain circumstances."

https://www.mixlycocktailco.com/blogs/news/does-tonic-water-go-bad

Why Does Tonic Water Glow Under UV Rays?

Tonic water glows and [sic] will fluoresce under UV rays because of quinine in it. Quinine is one of the most important alkaloids found in the cinchona bark, among many others. It has some rare earth compounds known as phosphors that glow when they hit certain wavelengths of the UV light. Phosphors in the quinine absorb the UV light and then reflect it or emit it again in the form of glowing blue light.

https://www.sawanonlinebookstore.com/why-does-tonic-water-glow-under-uv-rays/


Making magic mud – or not

Perhaps the most bizarre example was a site, 'emaze' which offered to show me "How to create magic mud…in 17 easy steps"

Step 1 was

"wash your potatoes!!!!"

However, perhaps due to exclamation fatigue(!), this went in a different, if now familiar, direction with step 2:

"Quinine contains rare earth compounds called phosphors. These substances glow when they are hit with particular wavelengths of the EM spectrum, including UV light. Phosphors absorb UV light and then emit it in their own color [sic, colour]. Thus, the black light's UV radiation is absorbed by the phosphors in the quinine, and then emitted again in the form of glowing blue light"

https://app.emaze.com/@AORQCIII#/16

This text was then repeated as each of steps 3-14. (Sadly steps 15-17 seemed to have been missed or lost. Or, perhaps not so sadly if they were just further repeats.) The first screen suggests this presentation was "done by Dr. Meena & Maha" but if Dr. Meena & Maha really exist (if you do, I am sorry, the internet makes me very sceptical) and 'done this', it is not clear if they got bored with their task very quickly, or whether the server managed to corrupt a much more coherent presentation when it was uploaded to the site.


This 'emaze' presentation seems to want to emphasise how quinine contains rare earth compounds…


According to Google, the site 'Course Hero' suggested

"Phosphors, which are found in quinine, are rare earth compounds. These chemicals glow when they are struck with particular wavelengths of the EM spectrum, …"

https://www.coursehero.com › Chemistry › 44733249–I…

but unfortunately (or perhaps fortunately given that snippet), the rest of the text seemed to be behind a pay-wall. This did not offer a strong incitement to pay for material on the site.

Toys coated with phosphorus?

Another website I came across was for a shop which claimed to be selling glow-in-the-dark objects that were made with phosoporus that needed to be illuminated to initiate a glow: a claim which seems not only scientifically incorrect (as mentioned above, phosphorus is not photoluminescent – it glows when in contact with air as it oxidises), and so unlikely; but, otherwise, dangerous and, surely, illegal.

Read about unscientific luminous creations

Defining scientific terms – badly

During my search, I came across a website (grammarist.com) offering to explain the difference between the words phosphorous and phosphorus. It did not discuss rare earths, but informed readers that

"Phosphate: Noun that means an electrically charged particle.
Phosphorus: Also a noun that means a mineral found in phosphate."
…We've already established that phosphorus is the simple mineral found in the particle phosphate, but phosphor is something else altogether."

https://grammarist.com/spelling/phosphorous-phosphorus/

So, that's 'no', 'no', 'no', and…I think at least one more 'no'.

Phosphorus is a reactive element, and is not found in nature as a mineral. To a scientist, a mineral is a material found in nature – as a component of rocks. Unfortunately, in discussing diet, the term minerals is often associated with elements, such as, for example, phosphorus, iodine, potassium and iron that are necessary for good health. However, one would not eat the element iron, but rather some compound of it. (Foods naturally contain iron compounds). And trying to eat phosphorus, iodine or potassium (rather than compounds of them) would be very hazardous.

So, whilst a nutritional supplement might well contain some minerals in the composition, strictly they are there as compounds that will provide a source of biologically important elements, and they will be metabolised into other compounds of those elements. (Iron from iron compounds will, for example, be used in synthesising the haem incorporated into red blood cells.) Unfortunately, learners commonly have alternative conceptions ('misconceptions') about the difference between mixtures and compounds and assume a compound maintains the properties of its 'constituent' elements (Taber, 1996).

"Compound is one or more elements mixed together"

alternative conception elicited from an Advance level chemisty student

The grammarist.com entry helpfully warned us that phosphate was "not to be confused with phosphoric acid, a chemical compound found in detergents and fertilizers". I suspect it is only found in detergents and fertilisers when something has gone wrong with the production process (notwithstanding diluted phosphoric acid has been used directly as a fertiliser) 4. It is a corrosive and irritant substance that can cause bronchitis – although tiny amounts are added to some colas. [n.b., cocaine also once featured in some cola, but that is no longer allowed.]

  • An ion is an electrically charged particle
  • The phosphate ion is one example of a type of ion.
  • Phosphates (such as calcium phosphate) are substances that contain phosphate ions.

So, phosphates contain electrically charged particles (phosphate ions), but that does not make phosphate an electrically charged particle, just as

  • blue does not mean a large marine mammal
  • bank does not mean a day of celebration where people do not need to go to work
  • vice does not mean a senior executive officer
  • motor does not mean a two wheeled vehicle
  • compact does not mean a flat circular object
  • final does not mean a simple musical instrument played with the breath
  • free does not mean a meal taken around noon or soon after, and
  • meal does not mean a token that provides entry or service

Grammarist invited feedback: I sent it some, so hopefully by the time you read this, the entry will have been changed.

It was on the internet: it must be true

The internet is an immense and powerful tool giving access to the vast resources of the World Wide Web. Unfortunately, the downside of a shared, democratic, free to access, reservoir of human knowledge is that there is no quality control. There is a lot of really good material on the web: but there is also a lot of nonsense on the web.

One example I have referred to before is the statement:

"energy is conserved in chemical reactions so can therefore be neither created nor destroyed"

This has the form of a logical structure

X so therefore Y

which is equivalent to

Y because X:

"energy can be neither created nor destroyed because it is conserved in chemical reactions"

This is just nonsense. There is no logical reason why the conservation of energy in chemical reactions implies a general principle of energy conservation.

We can deduce the specific from the general (days have 24 hours, so Sunday has 24 hours) but not the general from the specific (January has 31 days, so months have 31 days).

Perhaps this is easily missed by people who already know that energy is always conserved.

A parallel structure might be:

"association football teams always consist of eleven players so therefore sports teams always consist of eleven players"

"sports teams always consist of eleven players because association football teams always consist of eleven players"

This is 'obviously' wrong because we know that rugby teams and netball teams and volleyball teams and water polo teams (for example) do not consist of eleven players.

Yet, if you search for "energy can be neither created nor destroyed because it is conserved in chemical reactions", you will find that this claim is included on the public websites of many schools (Taber, 2020). That is because, despite being wrong, it has authority – it is included in the English National Curriculum for Science (which I find shocking – we all make mistakes, but did nobody check the document before publication?) The English government department responsible was made aware of the error but does not think that it is a priority to make corrections to the curriculum.

Artificial (ignorant) intelligence

But what about quinine containing rare earth compounds? A notion that is structurally similar to claiming that

  • France contains South American countries, or
  • 'Great Expectations' contains Jane Austin novels, or
  • February contains Autumn months, or
  • Cauliflower contains citrus fruits, or
  • Beethoven's 5th Symphony contains Haydn concerti

(in other words, something obviously silly to someone who has a basic understanding of the domain – chemistry or geography or literature or the calender or botany/horticulture or music – because it suggest one basic unit contains other units of similar status).

How does this error appear so often? Quite likely, a lot of website now are populated with material collected and collated by machines from other websites. If so, it only takes one human being (or government department) to publish something incorrect, and in time it is likely to start appearing in various places on the web.

There is currently a lot of talk of how artificial intelligence (AI) is getting better at writing essays, and answering questions, and even drafting lectures for busy academics. AI seemingly has great potential where it is provided with high quality feedback. Perhaps, but where the AI is based on finding patterns in publicly available texts, and has no real ability to check sense, then I wonder if the www is only going to become more and more polluted with misinformation and nonsense.

I do not know where Lucy Jane Santos got the idea that there are other substances in the single substance quinine (akin to having other countries in France), but if she did a web-search and relied on what she read, then I am in no position to be critical. I use the web to find things out and check things all the time. I am likely to spot gross errors in fields where I already have a strong background…but outside of that? I do seek to evaluate the likely authority of sources – but that does not mean I could not be taken in by a site which looked professional and authoritative.

The web started with imperfect people (because we all are) posting all kinds of material – with all kinds of motivations. I expect most of it was well-meaning, and usually represented something the poster actually believed; and indeed much of it was valid. However, a 'bot' can search, copy, and paste far quicker than a person, and if the internet is increasingly authored by programs that are indiscriminately copying bits and pieces from elsewhere to collage new copy to attract readers to advertising, then one cannot help wonder if the proportion of web-pages that cannot be trusted will be incrementally coming to dominate the whole network.

I (a fallible, but natural intelligence) hope not, but I am not very optimistic.


Work cited:


Notes:

1 Although my own research has been in science education and not one of the natural sciences, I am pleased that the learned societies (e.g. the Institute of Physics, the Royal Society of Chemistry, etc.) and the UK's Science Council, recognise the work of science educators as professional contributions to science.


2 One internet site suggests:

Luminescence is caused by various things like electric current, chemical reactions, nuclear radiation, electromagnetic radiation, etc. But phosphorescence takes place after a sample is irradiated with light.

• Phosphorescence remains for sometime even after the lighting source is removed. But luminescence is not so.

https://www.differencebetween.com/difference-between-luminescence-and-vs-phosphorescence/

The second paragraph is nonsensical since phosphorescence is a type of luminescence. (It should be, "…fluorescence" that does not.) The first paragraph seems reasonable except that the 'but' seems misplaced. However 'in the light of' the second sentence (which sees phosphorescence and luminescence as contrary) it seems that the (contrasting) 'but' was intended, and whoever wrote this did not realise that light is a form of electromagnetic radiation.

Another, more technical, site suggests,

Luminescence is the emission of light by a substance as a result of a chemical reaction (chemiluminescence) or an enzymatic reaction (bioluminescence).

https://www.moleculardevices.com/technology/luminescence

Here again a contrast is set up:

  • chemiluminescence (due to a chemical reaction) versus
  • bioluminescence (due to an enzymatic reaction).

However, the keen-eyed will have spotted that "an enzymatic reaction" is simply a chemical reaction catalysed by an enzyme. So, bioluminescence is a subtype of chemiluminescence, not something distinct.


3 Some sources claim that the medicinal properties of cinchona bark were discovered by Jesuit missionaries that travelled to South America as part of European imperial expansion there.

Nataly Allasi Canales of the Natural History Museum of Denmark, University of Copenhagen is reported as explaining that actually,

"Quinine was already known to the Quechua, the Cañari and the Chimú indigenous peoples that inhabited modern-day Peru, Bolivia and Ecuador before the arrival of the Spanish…They were the ones that introduced the bark to Spanish Jesuits."

https://www.bbc.com/travel/article/20200527-the-tree-that-changed-the-world-map

Learning about the history of indigenous technologies can be complicated because:

  • often they are transmitted by an oral and practice culture (rather than written accounts);
  • traditional practices may be disrupted (or even suppressed) by colonisation by external invaders; and
  • European colonisers, naturalists and other travellers, often did not think their indigenous informants 'counted', and rather considered (or at least treated) what they were shown as their own discoveries.

4 This again seems to reflect the common alternative conception that confuses mixtures and compounds (Taber, 1996): phosphoric acid is used in reactions to produce fertilizers and detergents, but having reacted is no longer present. It is a starting material, but not an ingredient of the final product.

Just as we do not eat iron and phosphorus, we do not use washing powders that contain phosphoric acid, even if they have been prepared with it. (Increasingly, phosphates are being replaced in detergents because of their polluting effects on surface water such as rivers and lakes.)


5 This gives the impression to me that the Department of Education sees schooling as little more than a game where students perform and are tested on learning whatever is presented to them, rather than being about learning what is worth knowing. There is surely no value in learning a logically flawed claim. Any student who understands the ideas will appreciate this statement is incorrect, but perhaps the English Government prefers testing for recall of rote learning rather than looking for critical engagement?