D BLOCK Flashcards
What groups in the periodic table make up the d-block?
Groups 3-12.
Which orbitals are progressively filled in the d-block elements?
The d orbitals.
How many long periods are there in the periodic table where the d-block elements are found?
Four long periods.
What does the f-block of the periodic table consist of?
Elements in which the 4f and 5f orbitals are progressively filled.
Where is the f-block placed in the periodic table?
In a separate panel at the bottom of the periodic table.
What is another name for d-block elements?
Transition metals.
What is another name for f-block elements?
Inner transition metals.
How many series of transition metals are there?
Four series: 3d, 4d, 5d, and 6d.
What elements make up the 3d series of transition metals?
Scandium (Sc) to Zinc (Zn).
What elements make up the 4d series of transition metals?
Yttrium (Y) to Cadmium (Cd).
Which elements are part of the 5d series of transition metals?
Lanthanum (La) and Hafnium (Hf) to Mercury (Hg).
What elements are included in the 6d series of transition metals?
Actinium (Ac) and elements from Rutherfordium (Rf) to Copernicium (Cn).
What are the two series of inner transition metals called?
Lanthanoids (4f series) and Actinoids (5f series).
What elements are included in the 4f series?
Cerium (Ce) to Lutetium (Lu).
What elements are included in the 5f series?
Thorium (Th) to Lawrencium (Lr).
Why were transition metals originally named so?
Because their chemical properties were transitional between those of s- and p-block elements.
How does IUPAC define transition metals?
Metals with incomplete d subshells either in their neutral atoms or in their ions.
Why are zinc (Zn), cadmium (Cd), and mercury (Hg) not regarded as transition metals?
They have a full d¹⁰ configuration in their ground state and common oxidation states.
Why are the chemistries of Zn, Cd, and Hg studied along with transition metals?
They are the end members of the 3d, 4d, and 5d transition series, respectively.
What makes transition elements different from other elements?
The presence of partly filled d or f orbitals in their atoms.
Can the usual theory of valence for non-transition elements be applied to transition elements?
Yes, the usual theory of valence can be successfully applied to transition elements as well.
Which precious metals belong to the transition metals series?
Silver, gold, and platinum.
Which industrially important metals are part of the transition metals series?
Iron, copper, and titanium.
Where is the d-block located in the periodic table?
In the large middle section, flanked between the s- and p-blocks.
Which orbitals receive electrons in d-block elements?
The d-orbitals of the penultimate energy level.
How many rows of transition metals are there, and what are they?
Four rows: 3d, 4d, 5d, and 6d.
What is the general electronic configuration of the outer orbitals in d-block elements?
(n-1)d^1-10 ns^1-2, except for palladium (Pd), which has 4d^10 5s^0.
What does (n-1) represent in the electronic configuration of d-block elements?
It represents the inner d orbitals, which may have 1 to 10 electrons.
How many electrons can the outermost ns orbital of d-block elements have?
One or two electrons.
Why are there exceptions to the general electronic configuration in d-block elements?
Because of the small energy difference between (n-1)d and ns orbitals, and the extra stability of half-filled and completely filled orbitals.
What is the electronic configuration of chromium (Cr) in the 3d series?
3d^5 4s^1 instead of 3d^4 4s^2.
Why does chromium (Cr) have an unusual electronic configuration?
The energy gap between the 3d and 4s orbitals is small, and the half-filled 3d^5 configuration is more stable.
What is the electronic configuration of copper (Cu) in the 3d series?
3d^10 4s^1 instead of 3d^9 4s^2.
Why does copper (Cu) have an unusual electronic configuration?
The completely filled 3d^10 configuration is more stable than 3d^9 4s^2.
What is the general electronic configuration of Zn, Cd, Hg, and Cn?
(n-1)d^10 ns^2.
Why are Zn, Cd, Hg, and Cn not considered transition elements?
Their orbitals are completely filled in both the ground state and their common oxidation states.
Why do the d orbitals of transition elements influence their surroundings more than s and p orbitals?
Because the d orbitals protrude to the periphery of an atom more than s and p orbitals.
What similarities do ions with a given d^n configuration (n = 1–9) exhibit?
They have similar magnetic and electronic properties.
What characteristic properties do transition elements exhibit due to partly filled d orbitals?
- Display of a variety of oxidation states. 2. Formation of colored ions. 3. Ability to form complexes with a variety of ligands.
What other properties do transition metals and their compounds exhibit?
Catalytic property and paramagnetic behavior.
Do transition elements show more similarities within a row or a group?
They show greater similarities in a horizontal row compared to non-transition elements, though some group similarities also exist.
What typical metallic properties do nearly all transition elements display?
High tensile strength, ductility, malleability, high thermal and electrical conductivity, and metallic lustre.
Which transition elements are exceptions to having typical metallic structures at normal temperatures?
Zinc (Zn), Cadmium (Cd), Mercury (Hg), and Manganese (Mn).
Are transition metals generally hard or soft?
Transition metals (except Zn, Cd, and Hg) are very hard.
What is the volatility of transition metals?
Transition metals (except Zn, Cd, and Hg) have low volatility.
How do the melting and boiling points of transition metals compare to other metals?
Transition metals have high melting and boiling points.
What series do the melting points of transition metals in Fig. 8.1 belong to?
The 3d, 4d, and 5d series.
Why do transition metals have high melting points?
Due to the involvement of a greater number of electrons from (n-1)d in addition to the ns electrons in interatomic metallic bonding.
In a row of transition metals, when do melting points reach a maximum?
At a d^5 configuration, except for anomalous values of Mn and Tc.
How do the melting points of transition metals change as the atomic number increases?
They fall regularly as the atomic number increases.
Why do transition metals have high enthalpies of atomisation?
Due to strong interatomic interactions, particularly when one unpaired electron per d orbital is present.
What does the maxima in enthalpies of atomisation at the middle of each transition series indicate?
It indicates that one unpaired electron per d orbital is particularly favorable for strong interatomic interaction.
How does the number of valence electrons affect bonding in transition metals?
Greater the number of valence electrons, stronger is the resultant bonding.
How does the enthalpy of atomisation influence the standard electrode potential of a metal?
Metals with very high enthalpy of atomisation tend to be noble in their reactions.
What property is associated with metals that have very high enthalpy of atomisation?
They tend to have very high boiling points and are more noble in their reactions.
What relationship exists between boiling point and enthalpy of atomisation for transition metals?
A very high boiling point corresponds to very high enthalpy of atomisation.
Why are metals with high enthalpy of atomisation considered noble in reactions?
Because strong interatomic interactions make them less reactive under standard conditions.
How do the enthalpies of atomisation compare between the first, second, and third series of transition metals?
The metals of the second and third series have greater enthalpies of atomisation than the corresponding elements of the first series.
What is a consequence of higher enthalpies of atomisation in second and third series transition metals?
It leads to more frequent metal–metal bonding in compounds of the heavy transition metals.
Why do second and third series transition metals exhibit more metal-metal bonding in their compounds?
Because they have greater enthalpies of atomisation, which strengthens interatomic interactions.
What happens to the radius of ions with the same charge in a series as atomic number increases?
The radius decreases progressively with increasing atomic number.
Why does the radius of ions decrease as atomic number increases?
Each added electron enters a d orbital, and the d electron shielding is ineffective, increasing net attraction to the nucleus.
What is the effect of a d electron on shielding?
The shielding effect of a d electron is not very effective.
How does ineffective shielding by d electrons affect ionic radius?
It increases the net electrostatic attraction between the nucleus and outermost electron, causing the ionic radius to decrease.
Is the trend of decreasing radius with increasing atomic number also observed in atomic radii?
Yes, the same trend is observed in the atomic radii of a given series.
How does the variation in atomic sizes within a series compare to variations between series?
The variation within a series is quite small, but differences are more significant when comparing between series.
How do atomic sizes change from the first (3d) to the second (4d) series?
There is an increase in atomic sizes from the first (3d) to the second (4d) series.
How do atomic radii of the third (5d) series compare to the second (4d) series?
The atomic radii of the third (5d) series are virtually the same as the second (4d) series.
What phenomenon explains the lack of size increase from the second to third series?
Lanthanoid contraction, caused by the filling of 4f orbitals, reduces the expected increase in size.
Why does the filling of 4f orbitals affect atomic radii?
The 4f orbitals have poor shielding, leading to a stronger nuclear attraction and smaller atomic sizes.
What is the primary cause of Lanthanoid contraction?
The poor shielding effect of 4f orbitals, which increases the effective nuclear charge experienced by outer electrons.
How does Lanthanoid contraction affect periodic trends of elements?
It reduces the expected increase in atomic and ionic radii down the group in the periodic table.
What is the impact of Lanthanoid contraction on chemical properties?
It makes the 5d series elements similar in size to the 4d series, affecting their chemistry and reducing variations across periods.
Why do 4f orbitals have poor shielding effects?
The 4f orbitals are more diffused and do not effectively shield the nuclear charge from the outermost electrons.
What is one observable consequence of Lanthanoid contraction in transition metals?
Transition metals in the 5d series have radii almost identical to their 4d counterparts.
How does Lanthanoid contraction influence the separation of Lanthanides?
The small differences in ionic radii among Lanthanides make their chemical separation challenging.
What is the net result of Lanthanoid contraction on the second and third d series?
The second (4d) and third (5d) d series exhibit similar radii (e.g., Zr 160 pm, Hf 159 pm) and have much more similar physical and chemical properties than expected based on usual family relationships.
Why do Zr (4d) and Hf (5d) have nearly identical radii?
Due to Lanthanoid contraction, the poor shielding of 4f electrons reduces the size of Hf, making its radius (159 pm) almost identical to Zr (160 pm).
How does Lanthanoid contraction affect the similarity in chemical properties between 4d and 5d elements?
The similar radii of 4d and 5d elements result in comparable chemical reactivity and bonding, making them behave similarly.
Which property of d-block elements is most influenced by Lanthanoid contraction?
Atomic and ionic radii are most influenced, leading to similarities between elements in the 4d and 5d series.
What is one industrial implication of Lanthanoid contraction?
The similarity in radii and properties of 4d and 5d elements, such as Zr and Hf, makes their separation during extraction processes challenging.
How does Lanthanoid contraction affect the trend in ionization energies?
The increase in effective nuclear charge due to poor shielding by 4f electrons leads to higher ionization energies for Lanthanides and their subsequent elements.
How does Lanthanoid contraction influence hardness and melting points?
Smaller atomic radii result in stronger metallic bonding, increasing hardness and melting points.
What is the primary factor responsible for Lanthanoid contraction?
The imperfect shielding of one 4f electron by another within the same orbital set.
How does the shielding effect of 4f electrons compare to that of d electrons?
The shielding of 4f electrons is less effective than the shielding of d electrons.
What happens to the size of the 4f orbitals as nuclear charge increases?
The size of the 4f orbitals decreases fairly regularly as the nuclear charge increases along the series.
How is Lanthanoid contraction similar to trends in ordinary transition series?
Both are caused by imperfect shielding of electrons within the same orbital set, leading to a decrease in atomic and ionic size with increasing nuclear charge.
How does the decrease in metallic radius and increase in atomic mass affect the density of elements?
The decrease in metallic radius and increase in atomic mass results in a general increase in the density of these elements.
How does the density change from titanium (Z = 22) to copper (Z = 29)?
There is a significant increase in the density from titanium (Z = 22) to copper (Z = 29).
What causes the density increase in transition metals from titanium to copper?
The decrease in metallic radius and the increase in atomic mass contribute to the overall increase in density.
Why do the transition elements exhibit higher enthalpies of
atomisation?
[intext]
Because of large number of unpaired electrons in their atoms they
have stronger interatomic interaction and hence stronger bonding
between atoms resulting in higher enthalpies of atomisation.
In the series Sc (Z = 21) to Zn (Z = 30), the enthalpy of atomisation
of zinc is the lowest, i.e., 126 kJ mol–1. Why?
[Intext]
In the formation of metallic bonds, no eletrons from 3d-orbitals are involved
in case of zinc, while in all other metals of the 3d series, electrons from
the d-orbitals are always involved in the formation of metallic bonds
