Consider the following transformation:
$2CuX_2 \xrightarrow{\text{Room temperature}} 2CuX + X_2 \uparrow$
Then $X^-$ can be:

Which of the following statements is $NOT$ consistent for transition elements?

Given below are two statements:
Assertion $(A)$: All $Cu$ $(II)$ halides are known except the iodide.
Reason $(R)$: $Cu^{2+}$ oxidizes $I^{-}$ to $I_2$.
The correct answer is:

Discuss the chemical properties of lanthanoids.

The copper $(II)$ halide which does not exist is:

Identify the incorrect statement.