What are the disadvantages of transition metal?

Answer 1

They're just so... transitioney.

This question makes no sense. There are no "disadvantages" of "transition metals" in general, you'd have to specify a particular application and a particular metal.

To give you an idea of what kind of range of properties we're talking about, iron and gold are both transition metals.

Answer 2

Transition metals can be toxic in high concentrations and can accumulate in the environment, causing pollution. They can also be expensive due to their rarity and difficult extraction processes. Additionally, some transition metals can be reactive and easily oxidize, leading to corrosion and degradation in certain applications.