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: An emotional facial expression ( EFE ) task consisting of a male and female face expressing six basic emotions ( happiness , surprise , sadness , anger , fear , and disgust ) was administered .
### Output Text:
An emotional facial expression ( EFE ) task consisting of a male and female face expressing six basic emotions ( happiness , surprise , sadness , anger , fear , and disgust ) was administered . 