The reduction in atomic size with increase in atomic
number is a characteristic of elements of

Which one of the following groups represent a
collection of isoelectronic species ?

The atomic numbers of vanadium (V). Chromium
(Cr), manganese (Mn) and iron (Fe) respectively
23, 24, 25 and 26. Which one of these may be
expected to have the higher second ionization
enthalpy ?

Which one of the following sets of ions represents
the collection of isoelectronic species ?

Which one of the following ions has the highest
value of ionic radius ?

Among Al2O3
, SiO2
, P2O3
and SO2
the correct order

of acid strength is

In which of the following arrangements the order is
NOT according to the property indicated against
it ?

Which of the following oxides is amphoteric in
character ?

Pick out the isoelectronic structure from the
following :
I. +CH3

II. H3O+
III. NH3

IV. CH3

The lanthanide contraction is responsible for the
fact that

Which of the following factors may be regarded
as the main cause the lanthanide contraction ?

The increasing order of the first ionization
enthalpies of the elements B, P, S and F (lowest
first) is –

Which one of the following sets of ions represents
a collection of isoelectronic species ?

lanthanoid contraction is caused due to -

Which one of the following has largest size ?

The decreasing order of the second ionization energy
of K, Ca and Ba is (At. Nos. K = 19, Ca = 20, Ba = 56)

Element Hg has two oxidation states Hg+1 & Hg+2
.

The right order of radii of these ions -

Which has most stable + 2 oxidation state :

Moving from right to left in a periodic table, the
atomic size is-

The increasing order of electronegativity in the
following elements-

One element has atomic weight 39. Its electronic
configuration is 1s2
, 2s2
2p6
, 3s2
3p6
4s1
. The true

statement for that element is-

The number of paired electrons in oxygen is -

Which of the following oxide is neutral ?

Which of the following has the maximum number of
unpaired electrons

The incorrect statement among the following is

The correct order of radii is -

The set representing the correct order of first
ionization potential is-

The correct order of acidic strength is -

Identify the least stable ion amongst the following-

Identify the correct order of acidic strengths of
CO2
, CO, CuO, CaO, H2O –