Which metal gives a blue borax bead?

The incorrect statement is:

The total number of $Mn=O$ bonds in $Mn_2O_7$ is

Identify the wrong statement regarding copper$(II)$ sulphate $(CuSO_4)$.

When dilute $H_2SO_4$ is added to an aqueous solution of potassium chromate,the yellow color of the solution turns to orange. What does this indicate?

$X$ is an oxoanion of the lightest element of group $7$ in the periodic table. The metal is in $+6$ oxidation state in $X$. The color of the potassium salt of $X$ is