I'm a huge fan of Mary Soon Lee's Elemental haiku on the website of Science Magazine. When you mouse over an element, you see a haiku that give you three lines' worth of information on that element's role in the world.
The poem for Na refers to the ion's role in the human nervous system:
Racing to trigger
every kiss, every kind act
behind every thought.
Poem for Boron:
Just doing your job
holding plant cells together
no fireworks, no fuss
Poem for Lithium:
Lighter than water
Empower my phone, my car
Banish depression
Poem for Chlorine:
Low road or high road?
World War I. Gas in trenches.Or salt shared, tears shed.
