Friday, December 02, 2005
Honors Periodic Table MC exam early results
I accepted two answers to question 26 because it is unfair to be asked to compare the size of a fluoride ion to the size of a calcium (2+) ion. Those particles have different Zeffs on their outermost PEL electrons and ALSO a different number of OPEL's. If you must know, the experimental data show that the calcium 2+ ion is about 37 pm smaller but I certainly do NOT want you to memorize or guess that.
p.s. as a result, everyone got that question right and there were at least six more perfect scores.
There also an active metal question (Na vs. Ca) that is a close call so I am accepting both answers ( though sodium is a bit more active ). Good times.
That said, the results are (approximate until I enter them in my excel gradebook):
D and E Periods: 93 ( oh! it's on!)
B Period: 90
These averages will increase once I make the above corrections.
Good work! Have a great weekend!
p.s. as a result, everyone got that question right and there were at least six more perfect scores.
There also an active metal question (Na vs. Ca) that is a close call so I am accepting both answers ( though sodium is a bit more active ). Good times.
That said, the results are (approximate until I enter them in my excel gradebook):
D and E Periods: 93 ( oh! it's on!)
B Period: 90
These averages will increase once I make the above corrections.
Good work! Have a great weekend!
# posted by C @ 6:27 PM 
