Which of the following transition metals has the lowest density?

Which of the following elements are included in the fourth transition series?

Assertion : $E^o$ for $Mn^{3+}/Mn^{2+}$ is more positive than $Cr^{3+}/Cr^{2+}$.
Reason : The third ionization energy of $Mn$ is larger than that of $Cr$.

Arrange the following elements in the increasing order of the number of unpaired electrons in them.
$A$. $Sc$ $B$. $Cr$ $C$. $V$ $D$. $Ti$ $E$. $Mn$
Choose the correct answer from the options given below:

Which of the following has the highest paramagnetic character?

Which of the following is $NOT$ a physical or chemical characteristic of interstitial compounds?