Welders need to know a lot about metals including their physical properties. Please especially refer to Table 1-2-Mechanical Properties of Metals/Alloys within the article. Listed in the table, in descending order, are a number of mechanical properties including malleability.
The following information provides an easy to follow explanation of the physical property of malleability. Examples are also included to help better understand this concept.
Described within this video are examples of metallic bonds. It's important to understand metallic bonds because it explains why metals act they way they do. Malleability is specifically explained in the following time frame: 2:25-3:00.