Which of the following elements is not considered a transition element?

Which of the following pairs of ions are colourless?

The correct statement about iron includes:
$I$) The highest oxidation state of iron is $+ 6$ in $K_2FeO_4$.
$II$) The iron shows $+ 2$ oxidation state with six electrons in the $3d$ orbitals.
$III$) The common oxidation state of iron is $+ 3$ with five unpaired electrons in the $3d$ orbital.

Given below are two statements:
Statement $I$: $Cr^{2+}$ is oxidising and $Mn^{3+}$ is reducing in nature.
Statement $II$: $Sc^{3+}$ compounds are repelled by the applied magnetic field.
In the light of the above statements,choose the most appropriate answer from the options given below:

Invar,an alloy of $Fe$ and $Ni$,is used in watches and meter scales. Its characteristic property is:

Ionisation potential values of $d-$block elements as compared to ionization potential values of $f-$block elements are