Page 15 - Microsoft PowerPoint - lecture1.ppt

2.1 Basics of Structures

Trends of the ionic radii

• ionic radii increase on going down a group

• radii of equal charge ions decrease cf. atomic radii

across a period

• ionic radii increase with increasing

coordination number (the higher its CN the

bigger the ions seems to be !!)

• the ionic radius of a given atom decreases

3+
2+
with increasing charge (r(Fe ) > r(Fe ))
• cations are usually the smaller ions in a
cation/anion combination

(exception: r(Cs ) > r(F ))
+
-