Final answer:
The best safety practices when using chemicals involve observing reactions, avoiding direct smelling of mixed chemicals, and using clean equipment for measurements.
Explanation:
Chemical Safety Practices in the Lab
- Mischa observes the reaction when he pours water into a bottle of acid. This demonstrates caution and awareness, ensuring safe handling of chemicals.
- Lena holds a flask under her nose to smell some liquids she mixed in it. Smelling mixed chemicals directly can be hazardous and unsafe.
- Janelle uses a clean spatula when measuring chemicals out of a bottle. Using clean equipment prevents contamination and promotes safety.
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