Iron $(Fe)$ is classified as:

The period number and group number of Tantalum $(Z = 73)$ are respectively:

In the electronic configuration of which of the given elements,$Aufbau$ principle or $(n+l)$ rule is violated?

The correct statement$(s)$ about $Cr^{2+}$ and $Mn^{3+}$ is(are)
[Atomic numbers of $Cr = 24$ and $Mn = 25$]
$(A)$ $Cr^{2+}$ is a reducing agent
$(B)$ $Mn^{3+}$ is an oxidizing agent
$(C)$ Both $Cr^{2+}$ and $Mn^{3+}$ exhibit $d^4$ electronic configuration
$(D)$ When $Cr^{2+}$ is used as a reducing agent,the chromium ion attains $d^3$ electronic configuration

Which of the following statements is true for transition elements?

The transition metals exhibit higher enthalpies of atomisation due to