NSES Content Standard B 
Physical Science: Properties of objects and materials 
Grades K-4, page 127 

Objects are made of one or more materials, such as paper, wood, and metal. Objects can be described by the properties of the materials from which they are made, and those properties can be used to separate or sort a group of objects or materials. 

Benchmark 4D The Physical Setting: Structure of Matter
Grades 3-5, page 77
When a new material is made by combining two or more materials, it has properties that are different from the original materials. For that reason, a lot of different materials can be made from a small number of basic kinds of materials.

Benchmark 8B The Designed World: Materials and Manufacturing
Grades 3-5, page 188
Naturally occurring materials such as wood, clay, cotton, and animal skins may be processed or combined with other materials to change their properties.