Question

1. the mortar and pestle should be used to _______ substances. you should grind only ____ substance at a time, and then clean the mortar and pestle before grinding another substance.

grind, one
burn, two
weigh, one
observe, one

1. what should you do before handling chemicals?

read the label and become familiar with all the safety issues relevant to handling that particular substance.
begin the experiment immediately
consult your lab partner
skim over the procedure

Explanation:

• For the first question, a mortar and pestle is a tool used to grind substances. And it is correct to grind only one substance at a time to avoid contamination.
• For the second question, safety is crucial when handling chemicals. Reading the label and understanding safety issues related to the specific substance is a fundamental safety - related action. Beginning the experiment immediately without proper knowledge is dangerous. Consulting a lab partner may not be sufficient as they may also lack knowledge. Skimming over the procedure is not a proper way to ensure safety.

Answer:

1. grind, one
2. Read the label and become familiar with all the safety issues relevant to handling that particular substance.