Periodycal #10: Easter chemistry special

An egg-cess of Easter chemistry graphics and celebrating ferrocene

Apr 7, 2023

Welcome to another edition of the Periodycal newsletter! Coming to you slightly later in the week than usual but just in time for some Easter-themed chemistry, including egg-dyeing, eggs themselves, and chocolate. There’s also a graphic celebrating ferrocene, the compound that revolutionised organometallic chemistry, the usual round-ups of chemistry tie-ins for upcoming events and celebrations, and interesting chemistry news and features.

Eggs and egg-dyeing

Graphic highlighting some of the different substances that can be used to dye egg shells various colours and the chemical structures of their dyes. Beetroot (red from betanin), red cabbage (blue from anthocyanins) and turmeric (yellow from curcumin) are highlighted. — Click to download a PDF of this graphic on the C&EN site

Dyeing egg shells in various colours is a common Easter activity, and this graphic highlights several different substances that can be used to create various colours, as well as the structures behind the differing hues.

Obviously, this is just a selection of the substances that can be used for egg dyeing. If you’ve tried it and found you had success with other substances, share them in the comments below!

Chocolate chemistry

Infographic looking at the differences between dark, milk and white chocolate. Dark chocolate has the highest percentage of cocoa solids and consequently higher levels of theobromine, which is toxic to dogs. White chocolate doesn't contain any cocoa solids. — Click to view and download the full graphic on the C&EN site

For those of us who celebrate Easter, chocolate eggs are a popular part! Here’s a reminder of some of the chemistry behind the different varieties of chocolate. Note that rose chocolate isn’t included as it wasn’t a thing when this graphic was put together back in 2016 – maybe a topic for a future graphic!

Making molecular sandwiches

An infographic describes the history of ferrocene and the chemistry and uses of other sandwich compounds. Researchers discovered ferrocene and determined its structure in the 1950s. The 1973 Nobel Prize in Chemistry was awarded to Geoffrey Wilkinson and Ernst Otto Fischer for their determination of ferrocene's structure and subsequent research on sandwich compounds. Researchers have also made compounds like ferrocene with variations to the central metal or the molecules around it. Sandwich compounds have been used in glucose sensors and as antiknock agents in gasoline. — Click to view and download full graphic on the C&EN site

This year marks 40 years since the Nobel Prize in Chemistry was awarded to Geoffrey Wilkinson and Ernst Otto Fischer for their work on the determination of ferrocene’s structure and subsequent research on sandwich compounds. The latest edition of Periodic Graphics in C&EN looks at the history of ferrocene, other types of sandwich compounds, and some of their everyday applications.

Upcoming chemistry tie-ins

Here’s a quick run-down of upcoming events or days and links to some relevant chemistry graphics from the archives:

April: International Guitar Month — The chemistry of an electric guitar
13 April: National Scrabble Day — The periodic table of element scrabble scores
15 April: World Art Day — Inorganic Pigment Compounds – The Chemistry of Paint
16 April: Day of the Mushroom — The chemistry of poisonous mushrooms
19 April: National Garlic Day — What compounds cause garlic breath?

Chemistry news and features

Here’s the regular round-up of chemistry news and features I’ve found interesting over the past couple of weeks:

The musical periodic table — Using a computer code, a researcher in the US has turned spectra of each of the elements into unique music, creating a musical periodic table of the elements. The results are, frankly, a bit atonal, so don’t expect any element earworms…
Experts condemn UK government’s decision to criminalise nitrous oxide — The UK government, which famously had enough of experts several years ago, continues to give their advice short shrift. The latest decision to ban nitrous oxide comes in spite of a review earlier in the year recommending the government didn’t move to ban it.
It’s still a bad idea to mix bleach and acidic cleaners.

Thank you for reading Periodycal – The Compound Interest Newsletter. This post is public so feel free to share it.

That’s it for another edition! Just time to say thanks to those of you who commented last issue on the wide variety of foods which can poison dogs – likely graphic on this upcoming!

Thanks for reading,

Andy