The electronic configuration of a metal element is given below:
$M = 1s^2 2s^2 2p^6 3s^2 3p^6 3d^{10} 4s^1$
To which block does this element belong?

Most transition metals exhibit several characteristic properties. Which of the following statements are correct?
$I$: Form sets of compounds which display different oxidation states of the metal.
$II$: Form coloured ions in solution.
$III$: Burn vigorously in oxygen.
$IV$: Act as catalysts.

The spin-only magnetic moment value of $M^{3+}$ ion (in gaseous state) from the pairs $Cr^{3+}/Cr^{2+}$,$Mn^{3+}/Mn^{2+}$,$Fe^{3+}/Fe^{2+}$,and $Co^{3+}/Co^{2+}$ that has a negative standard electrode potential,is $B.M.$ (Nearest integer).

The aqueous solution containing which one of the following ions will be colourless?

Identify the element having the highest first ionisation enthalpy $(IE_1)$ from the following.

The correct order of the first ionization enthalpies is: