d and f block Flashcards
(89 cards)
The elements belonging to
groups 3 to 12 are called
d-block or transition elements
what are f-block elements
The f-block consists of elements in which 4 f and 5 f orbitals are progressively filled. also called as inner transition metals
The general electronic configuration of
transition elements is
(n-1)d(1-10) ns (0 1 2)
There are mainly four series of the transition metals which are?
3d series (Sc to Zn), 4d series (Y to Cd), 5d series (Laand Hf to Hg) and 6d series which has Ac and elements from Rf to Cn
The two series of the inner transition
metals are?
The two series of the inner transition
metals; 4f (Ce to Lu) and 5f (Th to Lr) are known as lanthanoids and actinoids respectively
which elements of group 12 have full d
10 configuration not regarded as transition metals
zinc cadmium and mercury
the expectation element of 3d series are
copper and chromium
both metallic and covalent bonding is present in the atoms of transition elements. why?
The metallic bonding is due to possession of one or two electrons and The presence of unpaired and unfilled d-orbitals favours covalent bonding.
Greater the number of unpaired d electrons, greater the number of covalent
bonds and therefore, greater is the strength of these bonds
facts
why are metals like Cr Mo and W very hard and metals like Zn Cd and Hg very soft
Greater the number of unpaired d electrons, greater the number of covalent bonds and therefore, greater is the strength of these bonds thats why s. Cr,
Mo and W are very hard metals as they have maximum number of unpaired d-orbitals while Zn, Cd and Hg are softer in nature as they do not have any unpaired d-orbitals.
In the first transition series, the atomic
radius gradually decreases from _____ to ______but from _______ to _____, it is nearly the same.
scandium to chromium but from chromium to copper
The decrease in atomic radii in each series, in the beginning,
is due?
to an increase in nuclear charge from member to member which tends to pull the ns electrons inward, i.e., it tends to
reduce the size
why is there no change in atomic radii in mid way of the series?
there are operating two effects namely screening effect and nuclear charge effect which oppose each other. In the
midway onwards of the series both these effects become nearly equal and thus, there is no change in atomic radii inspite
of the fact that atomic number increases gradually.
why is there an increase in atomic radii at the end of the series
This is due to electron-electron repulsions among (n - 1)d electrons. These repulsions become predominant at
the end of each series and thus size increases.
the transition metals of third
series except the fIrst member, lanthanum, have nearly the same radii as metals of second transition series above them. This is due to?
Lanthanide contraction
vertical row, the atomic radii is expected to ________ from top to bottom. T
increase
the ionic radii generally ______ as
the atomic number increases in a particular transition series
decreases
The ionic radii________ with increase of charge on the ion
decreases
all the transition elements except __ ,_____and ___ possess density higher than 5 g mL -1
scandium, yttrium and titanium
The two elements ___and___ have high densities
osmium and iridium
_______ has the highest melting point
Tungsten
the melting points of transition elements ______ on increasing atomic number
decrease
The smaller the value of total energy change for a particular oxidation state in aqueous solution, greater will be the stability of that oxidation state.
facts
which element doesn liberate hydrogen from dilute acids
copper(only reacts with oxidizing acids like h2so4 and hno3) and chromium(due to form of cr2o3 oxide)
