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 administration of calcium chloride rapidly resolved the patient ' s tetany with prompt recovery of respiratory function , averting the need for more aggressive airway management and ventilatory support .
### Output Text:
The administration of <span class="chemical">calcium chloride</span> rapidly resolved the patient ' s tetany with prompt recovery of respiratory function , averting the need for more aggressive airway management and ventilatory support . 