Here's why:
* Malleability: The ability of a metal to be hammered or pressed into thin sheets. Technetium is a very hard metal, making it difficult to deform in this way.
* Ductility: The ability of a metal to be drawn into thin wires. Like malleability, technetium's hardness makes it unsuitable for drawing into wires.
While some sources might mention technetium as being malleable, its properties are generally considered to be more akin to those of brittle metals.
