Charge evaluator to grade chemistry answers

Updated 30 Aug 2024

Use the Charge answer evaluator (expressionOchemEvalCharge) to compare the total charge for any compound or set of compounds in the student’s response with the value indicated. The Charge evaluator works with the skeletal answer type.

Select Grade as Correct or Grade as Incorrect, then enter the conditions you want to be checked in student answers.
Select either the response has or the number of compounds in the response that have.
Select a total charge option from the ones provided, like exactly or other.
“Total charge of” options
exactly
Student answer number = the number in this box
more than
Student answer number > the number in this box
fewer than
Student answer number < the number in this box
not exactly
Student answer number <> the number in this box
fewer than or equal to
Student answer number ≤ the number in this box
more than or equal to
Student answer number ≥ the number in this box
Enter an integer charge value. The value can be either positive or negative, such as 1 or -1.
If you chose the number of compounds in the response that have in step 2, follow steps 3 and 4 to fill in the last two boxes to complete all of the conditions.