Z has only one valence bond, so it must be F or Cl, and their outermost electron number is 7. X has twice the number of electrons as 7, which is 14, so X is Si. Because they are the same periodic elements, Z is Cl.

W is a cation with a valence of+1, so it is Na. Finally, y, we can write a chemical formula, NaY(SiCl3)2. As a complete group, SiCl3 is the valence of+1, while Na is the valence of+1, so according to the algebraic sum of valence, it is 0 and y is the valence of -3, so it can only be used.

WZ, sodium chloride, neutral aqueous solution, a mistake.

Non-metal, silicon & gtP & gtCl? It's the opposite, so B is wrong.

The highest valence oxyacid of Y is H3PO4, phosphoric acid is a medium strong acid, and C is right.

Y does not satisfy the 8-electron structure? Of course. Y is -3, which means there are 3 electrons in the outermost layer. Y itself has five electrons in the outermost layer, which adds up to eight electrons. D is wrong.