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: Among the 39 reports that included information on race , the racial distribution was : 1 Black , 3 Caucasian , and 35 Asian .
### Output Text:
Among the 39 reports that included information on race , the racial distribution was : 1 Black , 3 Caucasian , and 35 Asian . 