It's a collaborative project so you can submit your own :-) (It appears from some of the author comments that several were submitted as a school project so there are kids helping out too :-)
Here's a couple for Calcium:
Humpty Dumpty sat on a wall.
Humpty Dumpty had a great fall.
All the King's chemists
And all the King's chums
Couldn't repair his calcium.
Picked up the pieces, each shard of shell.
Finished their work before it started to smell.
Cremated the albumen
Along with the yoke,
Believe it or not, it hadn't even broke.
Placed all the pieces in a small Easter basket.
Humpty lay shattered on straw in his casket.
During the service
The mood was placid.
When it was finished, dissolved Humpty in acid.
by Rusty Myers
Calcium, an element that’s not unknown,
Is found in milk and helps build a strong bone.
It’s a chemical element that is solid;
With the symbol Ca it is not squalid.
Calcium appears as silvery white
And although it’s soft it puts up a fight.
It’s located in group two, period four
And is an element you cannot abhor.
Calcium, in Latin meaning Lime,
Was found by Ancient Romans early in time.
It was isolated in 1808
By Sir Humphry Davy’s natural fate.
by Jessica Abercrombie