diff --git a/mechanical/mmme1029_materials.md b/mechanical/mmme1029_materials.md
index 288d47b..ebdc78f 100755
--- a/mechanical/mmme1029_materials.md
+++ b/mechanical/mmme1029_materials.md
@@ -661,7 +661,7 @@ $$C_pm = \frac{\Delta E}{n\Delta T}$$
 
 ~ [Wikipedia: Mole (unit)](https://en.wikipedia.org/wiki/Mole_(unit))
 
-<details>
+</details>
 
 <details>
 <summary>