Covalent bonds > hydrogen bonds

See, it's funny because covalent bonds are stronger than hydrogen bonds, and this 'cartoon' is using the weak versus strong password box that most of us are familiar with to comment on this strength difference.

Hydrogen bonds are usually considered to be intermolecular forces attracting separate molecules to each other (or parts of one molecule to different parts of the same molecule as in DNA and proteins' tertiary structures).

Covalent bonds, on the other hand, are intramolecular forces holding atoms together within molecules. They aren't usually considered IMFs unless we get into the grey area of covalent network solids.

I hope this goes chiral.

So, a little background...

There are certain molecules that exist in two mirror forms of each other. They have the same four functional groups around a single atom but arranged in such a way that they are mirror images of each other but cannot be rotated in such a way so as to superimpose one molecule onto the other.

These molecules are called chiral. They show chirality.

This is the opposite of achiral structures that are identical to their mirror image but can be rotated in such a way so as to superimpose one molecule on the other. A sphere, for example is achiral. It's identical to its mirror image, but the sphere can be rotated so that it matches its mirror image, too.

Samuel L Jackson is chiral, however, because he is identical to his mirror image, but there is no way to rotate him so that he is identical to his mirror image.

That's the first part.

The second bit of background is that the two forms of chiral molecules in chemistry are referred to as being levorotary and dextrorotary because they each rotate the polarization plane of light either left (levo-) or right (dextro-). To shorthand this, the molecules are labeled as L- or D- such as L-alanine and D-alanine. 

So, after all that, this is funny because it's Samuel L. Jackson would be an enantiomer (the chiral version) of Samuel D. Jackson.

Weirdly this chirality has been hypothesized to present a problem to life from 'our world' as the opposite chiral version of molecules such as protein from a 'mirror world' would likely not be useful in cellular processes if brought into our world. Just this past year I read an admittedly not great run of the Fantastic Four that used this concept as a problem that the First Family of Marvel had to solve.

A painfully incorrect graphic

Source - macosicons.com/#/u/antonin1802

The reddit thread on which I found today's graphic saw quite a few comments pointing out the horrific incorrectnesses (sp?) in the folder graphic found to the right.

Amongst the many issues...

• The chemical reaction as written eschews an arrow (or even equilibrium arrows) in favor of an equal sign. For people who don't know chemistry, those symbols might seem equivalent, but they are not - in spite of what some of my students have dismissively claimed over the years.
• The reactants in the reaction includes monatomic oxygen, a drastically and dangerously unstable form of oxygen. Typically, diatomic oxygen is written in the reactions because that's the stable form of elemental oxygen.
• The structural formula as drawn contains a carbon at the center top of the 'molecule' that has six bonds, expanding the octet of carbon which - to my understanding - is rather impossible.

There is some suggestion in a few of the comments that this figure might be generated by artificial intelligence. I can't speak to that, but if it was created by a human - assumedly antonin1802 - then it was clearly created by a human who didn't know how organic chemistry works.

Australia

 

See, it's funny because Au is the symbol for the element gold, so Au-stralia would be a stralia made of (or maybe colored) gold.

Ag-stralia would be a stralia made of silver because Ag is the symbol for silver.

Cu-stralia then would be a copper stralia because Cu is the symbol for copper.

You can read more about these element's - and eight more elements - symbol origins in this infographic from Compound Interest.

Science in an Art Museum, Part 1: The Science (and parts 2, 3, and 4, too)

As I mentioned last week, I toured the Indianapolis Art Museum's conservation lab as part of our summer ASM materials camp a decade or so ago. It was a great tour given by Dr Gregory Smith, star of this series of videos through which he explains the process of verifying the age and pedigree of an Uzbek Coat of Many Colors.

The rest of the four-part series is after the jump.