Rank each set of ions in order of decreasing size and explain your ranking
A) Ca+2, Sr+2, Mg+2
B)K+, S2-, Cl-
C) Au+, Au+3,
Answer:
A) Mg+2 < Ca+2 < Sr+2 All these ions are from group 2A so size increases down the group
B) K+ < Cl- < S2- These ions are isoelectronic, so size decreases as nuclear charge increases
C) Au+3 < Au+ Cation decreases as charge increases