April 2020
Intermediate to advanced
296 pages
5h 20m
English

When first dissolved in HCl, Ir revealed such hues,
So rare it sits in Pt’s group, corrosion it eschews.
Help’d set our standard length and mass,
aytch-see-ell eye-arr
GROUP 9 TRANSITION METAL
Iridium is a hard (yet brittle), lustrous metal that sits at the crossroads of row 6 and group 9 on the periodic table. English chemist Smithson Tennant discovered iridium in 1803. Tennant named the element after Iris, the Greek goddess of rainbows: he noted, “I should ...