The amphoteric oxide among $V_2O_3$,$V_2O_4$,and $V_2O_5$ upon reaction with alkali leads to the formation of an oxide anion. The oxidation state of $V$ in the oxide anion is:

Given below are two statements:
Statement $I :$ Potassium permanganate on heating at $573 \ K$ forms potassium manganate.
Statement $II :$ Both potassium permanganate and potassium manganate are tetrahedral and paramagnetic in nature.
In the light of the above statements,choose the most appropriate answer from the options given below.

Which of the following has conductivity and appearance like that of copper metal?

$MnO^{-}_4$ is of intense pink colour,though $Mn$ is in $(+7)$ oxidation state,it is due to

Silver halides are used in photography because:

Iron on reacting with carbon gives: