Are elements always transparent

No, the elements are not always transparent.

Explanation:

The elements become transparent when the light passes through those elements. Transparency is caused because of the transmission and the passing of the light waves through these elements.

But the metals do not become transparent even when the light waves pass through these metals. Metals do not become transparent because the refractive index in them is very big.

with this one i know the answer in craters one reason i looked it up and i learned about it there is my evidence

in the analysis of systems that involve fluid flow, we frequently encounter the combination of properties u and pv.