Answer :
Final answer:
The compounds formed by elements X and Z, based on the number of valence electrons, are AlF3 for scenario a, Na3P for scenario b, MgO for scenario c, and a covalent compound like PH3 for scenario d, though the question misidentifies the last as ionic when it should be covalent.
Explanation:
The chemical formulas for the ionic compounds that would form from elements X and Z can be written by considering the number of valence electrons in each element and then combining them in such a way that the compound is electrically neutral.
- a. If X has three valence electrons (possibly element Al) and Z has seven valence electrons (possibly element F), they would likely form the compound XZ'3 since X will form a +3 cation and Z will form a -1 anion. The formula would then be X'3Z'3 or simply XZ, which could represent aluminum fluoride, AlF'3.
- b. If X has one valence electron (possibly element Na) and Z has five valence electrons (possibly element P), they would likely form the compound X'3Z since X will form a +1 cation and Z will form a -3 anion. The formula would then be X'3Z or Na'3P, which could represent sodium phosphide.
- c. If X has two valence electrons (possibly element Mg) and Z has six valence electrons (possibly element O), they would form the compound XZ'2 since X will form a +2 cation and Z will form a -2 anion. The formula would be XZ or MgO, which could represent magnesium oxide.
- d. If X has five valence electrons (possibly element P) and Z has one valence electron (possibly element H), they would likely form the compound X'3Z'5, as X will form a -3 anion and Z will form a +1 cation. The mistake here is that Z, with one valence electron (like hydrogen), does not form ionic compounds with nonmetals like element P; instead, they would form covalent bonds such as in phosphine, PH'3.
