In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: Repeat neuropsychological testing 7 weeks after discontinuation of the drug revealed dramatic improvement in IQ , memory , naming , and other tasks commensurate with clinical recovery in his intellectual capacity .
### Output Text:
Repeat neuropsychological testing 7 weeks after discontinuation of the drug revealed dramatic improvement in IQ , memory , naming , and other tasks commensurate with clinical recovery in his intellectual capacity . 