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: Compared with the control group , the patients were impaired on a processing speed task ( p = 0 . 032 ) and on a measure of immediate verbal memory ( p = 0 . 026 ) after controlling for the use of hormone replacement therapy in both groups .
### Output Text:
Compared with the control group , the patients were impaired on a processing speed task ( p = 0 . 032 ) and on a measure of immediate verbal memory ( p = 0 . 026 ) after controlling for the use of hormone replacement therapy in both groups . 