# Perl Variables for Chemistry Questions (Fill-in-the-Blank Mode)

The following reserved Perl variables are used to return information or set behaviors in questions that you create in WebAssign.

Variable

Description

$PAD Enables a pad for answering chemistry questions (and hides symbolic formatting help icon): $PAD='chem' enables chemPad.

$CHEM Sets the chemPad grading mode. $CP_MAX_WIDTH

Sets the maximum width of the chemPad tool, for example, $CP_MAX_WIDTH=400. $MARVIN

Displays the Marvin JS tool for answer entry and sets the Marvin JS mode, for example, $MARVIN='complete'. $MARVIN_START

Sets a template for a Marvin JS question, usually using a key generated with the Marvin JS Key Generation tool.