ell the teacher about any chemicals that were spilled in a lab. They'll need to know so they can help you clean it up safely.
You don't want to dump all chemicals down the drain, as they can mix and react dangerously. You never want to directly smell a chemical (remember, waft!) and make sure to never eat in the lab. Also, you don't want beakers or glassware near the edge of the counter, because they might get knocked off and break or spill onto something/someone. Hope this helps! :)