Pack 13 Chemistry

Chemistry is about the notation of the lab: element symbols, molecular formulas, ionic charges, pH values and isotopes. Every element symbol starts with a capital letter, so letter case matters on every board.

First you catch element symbols like H, He and Na, but spare he and HE. Then come formulas like H2O and NaCl, charges like 2+, pH values from 0 to 14 with one optional decimal, and isotopes like C-14 and U-235. The formula board is a good test of repeating a group with an optional count.

Every level also has hidden checks: words you don’t see. Passing the words on screen solves a level; passing the hidden checks too ranks it.

The pH board is a small number-range problem, the same kind as the ones in Real-world formats. The Quantifiers track explains the optional and repeated parts used here.