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: The VAS scores for recall of pain in the recovery room were correlated with the VAS scores during induction ( r = 0 . 7045 ; P < 0 . 0001 ) .
### Output Text:
The VAS scores for recall of pain in the recovery room were correlated with the VAS scores during induction ( r = 0 . 7045 ; P < 0 . 0001 ) . 