diff --git a/docs/sch3uz.md b/docs/sch3uz.md
index b62fe7b..2be7c7e 100644
--- a/docs/sch3uz.md
+++ b/docs/sch3uz.md
@@ -703,6 +703,8 @@ Down a period, the number of shells occupied by the electrons increases, so vale
  - the attraction of valence electrons to the nucleus decreases due to the increasing distance
  - shielding increases due to the increasing number of electrons between the valence electrons and the nucleus
 
+The impacts of these basic concepts on the above periodic trends is left as an exercise to the reader.
+
 !!! example
     To explain why there is a trend of decreasing atomic radius across a period: