“The elements: perpetually trending!
Their table: conceptually tending
Some ranks qualitative
Regarding key data
Of species, location-depending.”
The 12 February 2020 limerick belatedly highlighted National Periodic Table Day, which I had not realized existed until its celebration on February 7… at which point I saw many pertinent Twitter hashtags!
“The elements: perpetually trending!”
The first line acknowledges the play on words with “trending” in a social media context and in a chemistry context.
“Their table: conceptually tending /
Some ranks qualitative /
Regarding key data /
Of species, location-depending.”
Information about elements’ behaviors can be understood from a reading of the periodic table of the elements (PTE), as described in lines two through five.
This is a poem in which the rhyme aligns fairly closely with the prose explanation. The periodic table organizes (“conceptually tends”) a wealth of general chemical and physical data about the elements (their “ranks qualitative”). In other words, once someone learns to read the PTE, they can use the placement of elements relative to one another to predict trends in these properties (“key data… location-depending”).
For instance, atomic radius (which essentially corresponds to atomic size) decreases left to right across a row of the PTE and increases down a column of the PTE. Thus, from looking at a periodic table, we know without having to research specific numbers that rubidium (Rb) would have a greater atomic radius than the element in the same column in the row directly above it: potassium (K). Correspondingly, potassium would have a greater atomic radius than its neighbor directly to the right: calcium (Ca). If we look these specific data up, we can confirm the trend: the respective atomic radii of Rb, K, and Ca are 235 picometers (pm), 220 pm, and 180 pm.
Countless other relationships can be described, for a variety of physical and chemical elemental behaviors. The PTE is an enormously useful reference tool, for scientists and science students around the world.
Chemphasis 