Question

On what basis can you say that scandium $\left( {Z = 21} \right)$ is a transition element but zinc $\left( {Z = 30} \right)$ is not?

Answer 1

We know that transitional metal is any of different synthetic components that have valence electrons—i.e., electrons that can partake in the arrangement of compound bonds—in two shells rather than just one. While the term progress has no specific compound importance, it's anything but a helpful name by which to recognize the closeness of the nuclear constructions and coming about properties of the components so assigned. They involve the center parts of the extensive stretches of the occasional table of components between the group on the left-hand side and the group on the right.

Complete answer:
Note that the component's mercury, cadmium, and zinc are not viewed as change components on account of their electronic designs, which compares to $\left( {n - 1} \right){d^{10}}n{s^2}$. These components have totally filled d orbitals in their ground states and surprisingly in a portion of their oxidation states. One such model is the $+ 2$ oxidation condition of mercury, which relates to an electronic setup of $\left( {n - 1} \right){d^{10}}$.
Based on deficiently filled $3d$ -orbitals if there should arise an occurrence of a scandium atom in its ground state ($3{d^1}$), it is viewed as a progress component. Then again, the zinc molecule has totally filled d-orbitals ($3{d^{10}}$ ) in its ground state just as in its oxidized state, thus it's anything but viewed as a change component.

Note:
Now we can discuss the subclasses of transition metals as early progress metals are on the left half of the intermittent table from group $3$ to group $7$ . Late progress metals are on the right half of the d-block, from group $8$ to $11$ (and $12$ on the off chance that it is considered change metals).