For each of the following statements, provide a detailed explanation:
a. The Cl- ion is larger than the Cl atom
b. The S2- ion is larger than the O2- ion
c. The K+ ion is larger than the Ca2+ ion
Consider what's different about each of the two ions you're comparing.
Also consider that the size of an atom is the physical distance from the core of the nucleus to the farthest point away from the nucleus in the outermost orbit of electrons.
Cl- has one more electron more than Cl.
The extra electron fills in the one empty spot in the valence shell (where Cl has 7 electrons, full valence calls for 8). However, electrons repel each other, and adding the extra electron causes the orbit of this valence shell to deviate just a little farther away ...
Ions and atom sizes are examined.