Question

This one cation and two anions each have 18 electrons. (The anions are found in table salt.) Your refrigerator may contain some sour items which have some of this compound. What is the compound’s name and formula?

Answer 1

You speak of calcium chloride......`CaCl_2`....

Explanation:

Table salt is `NaCl`, and thus the anion is `Cl^-`, for which `Z=17`.

And if there are TWO chlorides, the NEUTRAL salt must contain a doubly charge charged cation. And since this cation has 18 electrons, for the parent atom `Z=20`, i.e. the element is calcium. I am told that its salt, calcium chloride, is added to some cheese and yoghurt formulations....