I don’t get it. What is the question asking?
When we go to periodic table, Sulfur is
an element that has 16 protons and 16 electrons.
when there is 18 electrons, with number of two electrons more than protons. This makes it an ion and
the ion has a -2 charge.
So when there is16 protons, 18 neutrons, and 18 electrons the symbol is S⁻².
The neutrons have no charge but they add only mass to the
elements. So when there is 16 neutrons, it doesn't change the symbol of ion.
Answer:
Adding a solution containing an anion that forms an insoluble salt with only one of the metal ions.
Explanation:
The student have in solution Ag⁺ and Cu²⁺ ions but he just want to analyze the silver, that means he need to separate ions.
Centrifuging the solution to isolate the heavier ions <em>FALSE </em>Centrifugation allows the separation of a suspension but Ag⁺ and Cu²⁺ are both soluble in water.
Adding enough base solution to bring the pH up to 7.0 <em>FALSE </em>At pH = 7,0 these ions are soluble in water and its separation will not be possible.
Adding a solution containing an anion that forms an insoluble salt with only one of the metal ions <em>TRUE </em>For example, the addition of Cl⁻ will precipitate the Ag⁺ as AgCl(s) allowing its separation.
Evaporating the solution to recover the dissolved nitrates. <em>FALSE</em> . Thus, you will obtain the nitrates of these ions but will be mixed doing impossible its separation.
I hope it helps!
The answer to your question would be D Volumetric Flask