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: RESULTS : The results showed that IP administration of bupropion HCl 120 mg / kg by bolus injection induced convulsions in 6 out of 10 mice ( 60 % of convulsing mice ) in group 1 .
### Output Text:
RESULTS : The results showed that IP administration of <span class="chemical">bupropion HCl</span> 120 mg / kg by bolus injection induced convulsions in 6 out of 10 mice ( 60 % of convulsing mice ) in group 1 . 