試題詳解

29. The two compounds shown on the right are used to synthesize flame retardant materials and biomaterials. The atomic numbers of the elements W, X, Y and Z are known to be W<X<Y<Z<20，X and Z are in the same group, and the atomic number of Y is three times the

number of valence electrons of W. 

Which of the following statements is correct?
(A) The highest oxidation state of both X and Z is +7.
(B) Both HX and HZ are strong acids in water, and their electron dot structures can be expressed as

(C) Z, W, and hydrogen form a covalent compound, which is soluble in water.
(D) X and Z form compounds XZ, XZ₃, XZ₅ and XZ₇.
(E) Of these four elements, Y has the largest atomic radius, while X has the

smallest.