Question

emily spills concentrated sodium hydroxide solution on her lab bench. what she should do first?
notify her teacher.
clean up the spill herself.
clean up the spill with her classmates.
read the msds for sodium hydroxide.

Explanation:

In a laboratory setting, especially when dealing with a concentrated chemical like sodium hydroxide (which is corrosive), the first step is to notify the teacher. Teachers are trained to handle such situations safely. Cleaning up herself or with classmates could lead to improper handling (e.g., using wrong materials to clean, not knowing the full hazards). Reading the MSDS (Material Safety Data Sheet) would take time and is not the immediate first - step action compared to alerting a trained professional.

Answer:

Notify her teacher.