Copyright © 2008 Pearson Prentice Hall, Inc.
Chapter 4/
35
Oxidation-Reduction (Redox)
Reactions
2.
A monatomic ion has an oxidation number identical
to its charge.
Na
1+
+1
Ca
2+
+2
Al
3+
+3
Cl
1-
-1
O
2-
-2
This is why charges are supposed to be written as “1-”. The corresponding oxidation number is written “-1”.