I believe it means the imitations on what you did what were you not able to do to the object. I'm not too sure but I believe that's what it means. I hope I was able to help
"M" I believe is the symbol for molarity.
They vibrate back and forth
Answer:
<h2>Na^+ Cl^- > NaCl</h2>

<span>2 NaOH(aq)+ 2 Al(s)+ 2 H</span>₂<span>O → 2 NaAlO</span>₂<span>(aq)+ 3 H</span>₂<span>(g)
</span> 2mol : 2mol : 3mol
2,14mol : 1,89mol : 2,835mol
remains completely consumed
2,14-1,89=0,25mol
A) Al
B)

C)