ConcepTest: Identifying Oxides
and is replicated here as part of the SERC Pedagogic Service.
d. CaSO4 · 2H2O
The correct response is C.
Percentage of students choosing this answer. (% Before Discussion/% After Discussion):
a. FeS2 (6%/3%)
b. KalSi3O8 (10%/3%)
c. Fe2O3 (56%/84%)
d. CaSO4 · 2H2O (28%/10%)
in a small (< 60 students) environmental geology class
If you would like to help acquire more Before and After statistics for this example, please contact the authors (see link at top of page).