Why do 4d and 5d have the same radii?

The atomic radii of the second (4d series ) and third, (5d series) transition series are almost the same. This phenomenon is associated with te intervention of the 4f orbitals which must be filled before the 5d series of element begin.

Why the properties of 4d and 5d transition elements are similar?

In the same group of d-block elements, the 4d and 5d transition elements has larger size than that of 3d element. Thus, the valence electrons are less tightly held and hence can form metal-metal bond more frequently.

Why atomic radius of first row of the d-block elements are almost constant across the period?

The atomic radii of the first transition series decrease from Sc to Cr and remain almost constant till Cu and then increases towards the end. In elements of column 7 to 10 increasing effective nuclear charges are balanced by the repulsion between the shared d electrons so that radii remain the same.

Why do transition metals have similar atomic radii?

At the same time, in transition elements the number of electrons in the 3d sub-shell will increase. This will repel the already present 4s electrons. This repulsion will increase the atomic radius. In Fe, Co, Ni & Cu both the effects nearly balance each other keeping the atomic radius same.

How does the atomic radii of 3d transition series varies?

In 3d series, radius of Zn is greater than that of Cu. The thing that brings difference in atomic size is effective nuclear charge. When the increase in nuclear charge and shielding is different, atomic radius changes. When increase in nuclear charge is greater than increase in shielding, atomic radius decreases.

Why do transition metals and their compounds act as catalyst?

Answer : Transition metals and their compounds act as good catalysts due to its ability to show variable oxidation state and form complexes, another reason is that they provide a suitable surface for reaction to take place. Eg: Vanadium Oxide in contact process, Finely divided iron in Haber’s Process.

Why the transition element of 4d and 5d series resemble much more closely than their 3d analogues?

The 4d and 5d series of the transition metals have more frequent metal-metal bonding in their compounds than do the 3d metals because of higher enthalpies of atomisation of 4d and 5d as compared to 3d.

What are the transition elements explain why the transition elements of 4d and 5d series resemble much more closely than their 3d analogues?

The elements with highest enthalpy of atomisation tend to be noble metals. The 4d and 5d of transition metals shows greater enthapies of atomisation than the elements of 3d series due to which 4d and 5d of transition metals have more frequent metal-metal bonding in their compounds than 3d metals.

What is atomic radii of D block elements?

Atomic radii of the elements of the transition series decrease gradually from left to right. The result is that effective nuclear charge also increases as the atomic number increases along with a transition series. Hence, the atomic radii gradually decrease across a transition series from left to right.

What are transition elements explain why the transition elements of 4d and 5d series resemble much more closely than their 3d analogues?

What makes D block elements different from other blocks?

The d-block elements are all metals and most have one or more chemically active d-orbital electrons. Because there is a relatively small difference in the energy of the different d-orbital electrons, the number of electrons participating in chemical bonding can vary.

Why the atomic radii of 5d transition elements is same as 4D?

Why the atomic radii of 5d transition elements is same as 4d transition elements? The increase in size that arises due to period change or increase in shell number is almost compensated by lanthanide contraction. Lanthanide contraction is the gradual decrease in the atomic and ionic size of lanthanoids with an increase in atomic number.

Why are 5D elements smaller than their 4D counterparts?

The outer electrons (6s or 5d) are not shielded in a magnitude sufficient for the increase in attractive force because of the diffused shape of the f-orbitals and hence are pulled closer despite the increase in electronic shell (5s vs 6s). Hence, 5d elements are smaller or at least not bigger than their 4d counterparts.

Why is the volume density of 5D series transition elements double?

Due to lanthanide contraction and a larger decrease in atomic radii and hence, the volume density of 5d series transition elements are double than 4d series. In the 3d series, scandium has the lowest density and copper highest density.

How many electrons have been added to the 5D elements?

Now, as we have filled up the 4f-orbitals in the 5d elements, we have not just added 14 electrons, but we have also added 14 protons to the nucleus which exert a larger pull on the outer electrons.