diff --git a/mechanical/mmme1029_materials.md b/mechanical/mmme1029_materials.md
index 054c66b..ea0fe20 100755
--- a/mechanical/mmme1029_materials.md
+++ b/mechanical/mmme1029_materials.md
@@ -107,7 +107,9 @@ work:
 
 # Lecture 2
 
-## Metals
+## Properties of the Classes
+
+### Metals
 
 - Ductile (yields before fracture)
 - High UFS (Ultimate Fracture Stress) in tension and compression
@@ -116,7 +118,7 @@ work:
 - High melting point
 - High electric and thermal conductivity
 
-## Ceramics and Glasses
+### Ceramics and Glasses
 
 - Brittle --- elastic to failure, no yield
 - Hard (harder than metals)
@@ -129,7 +131,7 @@ work:
 - Poor thermal and electric conductivity
 - Wide range of magnetic and dielectric behaviours
 
-## Polymers
+### Polymers
 
 - Organic---as in organic chemistry (i.e. carbon based)
 - Ductile 
@@ -141,7 +143,7 @@ work:
 
   - There are some electrically conductive polymers 
 
-## Composites
+### Composites
 
 - Composed of 2 or more materials on any scale from atomic to mm scale to produce properties that
   cannot be obtained in a single material
@@ -150,13 +152,15 @@ work:
 
 - Material propertes depends on what its made of
 
-## Organic vs Inorganic Materials
+## Terms
+
+### Organic vs Inorganic Materials
 
 - Organic materials are carbon based
 - From chemistry, organic compounds are ones with a C-H bond
 - Inorganic compounds do not contain the C-H bond
 
-## Crystalline vs Non-Crystalline Materials
+### Crystalline vs Non-Crystalline Materials
 
 - Most things are crystalline
 
@@ -167,7 +171,10 @@ work:
   - Ceramics
 
 - Glasses are non-crystalline
-## Material Density
+
+## Material Properties
+
+### Density
 
 $$\rho = \frac m v$$
 
@@ -179,7 +186,7 @@ $$\rho = \frac m v$$
   e.g. composites with a metal matrix will have a much higher density than those with a polymer
   matrix
 
-## Material Melting Points
+### Melting Points
 
 - Measured at standard pressure and in an intert atmosphere (e.g. with Nitrogen, Argon, etc)
 
@@ -188,7 +195,7 @@ $$\rho = \frac m v$$
 
 - High melting points -> high chemical bond strength
 
-## Material Corrosion
+### Corrosion
 
 - It's not just metals that corrode