Which tool is specifically used to knock flakes from cores?

The tool specifically used to knock flakes from cores is the hammerstone. In stone tool technology, the hammerstone is a harder rock that is used to strike a core material, which is often made of a softer stone like flint or chert. The impact from the hammerstone creates flakes that can be removed and fashioned into tools. This technique is fundamental in lithic (stone) technology, where the process of flaking is essential for producing sharp edges useful for cutting and processing materials.

The other tools listed have different purposes. A chopper is typically a tool with a sharp edge on one side, used for cutting or chopping, rather than for striking flakes off cores. A blade is a thin, flat, and often sharp tool created from these flakes, and its function is post-flaking. A core refers to the main body of stone from which flakes are removed, but it does not itself interact with other materials to create the flakes. Understanding the specific role of the hammerstone in flaking processes highlights its importance in prehistoric tool-making techniques.