These crystals are in the puzzle below. Photo byÌýEd Escudero.Ìý
Printable PDF for Green Puzzle for St Patrick's Day
Which of the following are green?
☘ÌýÌý Ìý510 nm or 600 nm
☘ÌýÌý ÌýBromothymol blue in a basic solution or a neutral solution
☘ÌýÌý ÌýCopper(II) chloride dihydrate or copper(II) oxide
☘ÌýÌý ÌýBaCl2 salt or CaCl2 salt in fireworks
☘ÌýÌý ÌýFlame test for boron or sodium
☘ÌýÌý ÌýHematite or malachite
☘ÌýÌý ÌýAl2O3, with Cr3+ replacing a few Al3+ in octahedral sites orÌýBe3Al2(SiO3)6, with Cr3+ replacing a few Al3+ in octahedral sites
☘ÌýÌý ÌýPotassium ferric oxalate trihydrate or cupric sulfate pentahydrate crystals
Ìý
☘ÌýÌý ÌýCopper arsenite or cadmium sulfide paint (we would not suggest painting your room with either)
☘ÌýÌý ÌýC37H34N2Na2O10S3 or C37H34N2Na2O9S3 (note the small difference inÌýcompound but a difference in colour)
☘ÌýÌý ÌýUniversal pH test paper dipped in a weak alkaline or strong acidÌýsolution
Ìý
☘ÌýÌý ÌýChlorophyll under ultraviolet light or chlorophyll under visible light (front cover of this issue)
Reprinted from March 2007 issue of Chem 13 News with more comparisons added to challenge your students and you.ÌýÌýÌý Ìý☘
Ìý
