Which of the following compounds is amphoteric?

Which of the following statements is incorrect?

Identify correct statements from below:
$A$. The chromate ion is square planar.
$B$. Dichromates are generally prepared from chromates.
$C$. The green manganate ion is diamagnetic.
$D$. Dark green coloured $K_2MnO_4$ disproportionates in a neutral or acidic medium to give permanganate.
$E$. With increasing oxidation number of transition metal,ionic character of the oxides decreases.
Choose the correct answer from the options given below:

Which of the following statements are $INCORRECT$?
$A$. All the transition metals except scandium form $MO$ oxides which are ionic.
$B$. The highest oxidation number corresponding to the group number in transition metal oxides is attained in $Sc_2O_3$ to $Mn_2O_7$.
$C$. Basic character increases from $V_2O_3$ to $V_2O_4$ to $V_2O_5$.
$D$. $V_2O_4$ dissolves in acids to give $VO_4^{3-}$ salts.
$E$. $CrO$ is basic but $Cr_2O_3$ is amphoteric.
Choose the correct answer from the options given below:

State the uses of zinc and iron.

Which transition metal oxide among the following has electrical conductivity similar to that of copper?