Answer:
The answer would be C). All of the elements inside a period will always have the same amount of shells. Hope this helps!
<span>Balanced chemial equation:
2NaI(aq)+Hg2(NO3)2(aq) →Hg2 I2 (s) + 2 NaNO3 (aq)
You can see it better if I use latex:

As per the phases this is the interpretation:
The symbols (aq) stands for aquous meaning that the compound is dissolved in water.
The symbol (s) stands for solid, meaning tha the compound precipitate and is not dissolved in water.</span><span>
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The new volume of the oxygen would be 17.4 L. I think it's 17.4 L but I don't know. I hope it was helpful.
Answer: 0.0257 moles of
and 0.0257 moles of 
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per Liter of the solution.

moles of 
The balanced reaction for dissociation will be:
According to stoichiometry:
1 mole of
gives 1 mole of
and 1 mole of 
Thus there will be 0.0257 moles of
and 0.0257 moles of 