New D Block Elements

Question 1

The…………….. metals are defined as metals which have incomplete d subshell either in neutral atom or in their ions

Answer 1

Transition

Question 2

Nearly all the transition elements display typical metallic properties such as
(6)

Answer 2

High tensile strength
Ductility
Malleability
High thermal and electrical conductivity
Metallic lustre.

Question 3

The high……….of these metals are attributed to the involvement of greater number of electrons from (n-1)d in addition to the ns electrons in the interatomic metallic bonding.

Answer 3

melting points

Question 4

In any row the melting points of these metals rise to a maximum at d5 except for anomalous values of……. & …….. and fall regularly as the atomic number increases

Answer 4

Mn and Tc

Question 5

The maxima at about the middle of each series indicate that……. unpaired electron per d orbital is particularly favourable for strong interatomic interaction.

Answer 5

one

Question 6

Assertion: metals with very high enthalpy of atomisation (i.e., very high boiling point) tend to be noble in their reactions

Answer 6

Reason: Since the enthalpy of atomisation is an important factor in determining the standard electrode potential of a metal

Question 7

Assertion: The metals of the second and third series have greater enthalpies of atomisation than the corresponding elements of the first series
Reason: There is occurrence of much more frequent metal – metal bonding in compounds of the heavy transition metals.

Answer 7

Both are correct and correct explanation

Question 8

The………. in metallic radius coupled with……….. in atomic mass results in a general………. in the density of these elements along a series (L to R)

Answer 8

decrease
increase
increase

Question 9

In general, ions of the same charge in a given series show progressive……….. in radius with increasing atomic number

Answer 9

decrease

Question 10

Assertion: There is an increase from the first (3d) to the second (4d) series of the elements but the radii of the third (5d) series are virtually the same as those of the corresponding members of the second series.

Answer 10

Reason: This phenomenon is associated with the intervention of the 4f orbitals which must be filled before the 5d series of elements begin. The filling of 4f before 5d orbital results in a regular decrease in atomic radii called Lanthanoid contraction which essentially compensates for the expected increase in atomic size with increasing atomic number

Question 11

The values show that the successive enthalpies of these elements do not……… as steeply as in the case of non-transition elements

Answer 11

increase

Question 12

The first ionisation enthalpy, in general…….. but the magnitude of the increase in the second and third ionisation enthalpies for the successive elements, is much higher along a series.

Answer 12

increases

Question 13

The irregular trend in the first ionisation enthalpy of the metals of 3d series, though of little chemical significance, can be accounted for by considering that

Answer 13

the removal of one electron alters the relative energies of 4s and 3d orbitals.

Question 14

The three terms responsible for the value of ionisation enthalpy are……../………./………..

Answer 14

Attraction of each electron towards nucleus
Repulsion between the electrons
Exchange energy.

Question 15

Exchange energy is approximately proportional to the total number of possible pairs of ………… in the degenerate orbitals

Answer 15

parallel spins

Question 16

The lesser number of oxidation states at the extreme ends stems from either

Answer 16

Too few electrons to lose or share (Sc, Ti)

Too many d electrons (hence fewer orbitals available in which to share electrons with others) for higher valence (Cu, Zn).