The magnetic moment of $Mn^{4+}$ ion is approximately ...... $B.M.$

Which of the following statements is not true?

Which of the following statements are correct about $Zn, Cd$ and $Hg$?
$A$. They exhibit high enthalpy of atomization as the d-subshell is full.
$B$. $Zn$ and $Cd$ do not show variable oxidation state while $Hg$ shows $+I$ and $+II$.
$C$. Compounds of $Zn, Cd$ and $Hg$ are paramagnetic in nature.
$D$. $Zn, Cd$ and $Hg$ are called soft metals.
Choose the most appropriate from the options given below:

Explain briefly how the $+2$ oxidation state becomes more stable in the first half of the first-row transition elements as the atomic number increases.

Which of the following transition metals is considered the softest?

Which element from the following in $+3$ oxidation state forms colourless compounds?