Which of the following is not a Doeberiner triad

Which of the following set of elements obeyes
Newland’s octave rule -

Which is not anomalous pair of elements in the
Medeleeves periodic table -

The places that were left empty by Mendeleef were,
for -

Which of the following pairs of elements do not
follow octave rule -

Elements which occupied position in the lother
meyer curve, on the peaks, were -

Modern periodic table is based on atomic no.
experiments which proved importance of at no.
was -

Atomic wt. or Cl = 35.5 and of I = 127. According to
doeberiner triad rule, At. wt. of Br will be -

The elements of groups, 1, 2, 13, 14, 15, 16 and 17
are collectively called -

Justification of putting H in VII A group is -

The discovery of which of the following group of
elements gave a death blow to the Newlands Law -

Which of the following pair of elements follows
Newland’s octave rule -

From the list given below, elements which belongs
to the same group or sub-group are -

The name ‘Rare earths’ is used for -

Z/e ratio for N3–, O2– and F–

respectively will be -

There are 10 neutrons in the nucleus of the element
zM19. It belongs to -

For Rb(Z = 37), points out the number of electrons
present in L and N shells respectively

The electronic configuration of an element is 1s2
,

2s22p6
, 3s23p4
.The atomic number of element
present just below the above element in periodic
table is -

The number of elements in 5th and 6th period of
periodic table are respectively -

Atomic number of Ag is 47. In the same group the
atomic number of elements placed above and below
Ag will be -

Atomic number 15, 33, 51 represents the following
family -

The atom having the valence shell electronic
configuration 4s2
4p2
would be in -

The number of elements know at that time when
Mendeleev arranged them in the periodic table was-

As applied to periodic table, which of the following
sets include only magic numbers -

In the general electronic configuration -
(n – 2)f1–14 (n – 1)d0–1 ns2

, if value of n = 7 the

configuration will be -

The correct order of atomic size of C, N, P, S
follows the order

The ionic radii of N3–, O2– and F–

are respectively

given by -

The screening effect of d-electrons is -

In which of the following compounds manganese
show maximum radius -

Arrange in the increasing order of atomic radii of
the following elements O, C, F, Cl, Br

In the ions P3–, S2– and Cl–

the increasing order

of size is -

Atomic radii of Fluorine and Neon in Angstrom
units are given by

Which of the following has largest radius -

Arrange the elements in increasing order of
atomic radius Na, Rb, K, Mg

Which of the following sequences is correct for
decreasing order of ionic radius -

The order of size is -

Arrange the following in order of increasing
atomic radii Na, Si, Al, Ar -

Consider the isoelectronic series :
K+
, S2–, Cl–
and Ca2+, the radii of the ions

decrease as

Which of the following is not isoelectronic series-

In the isoelectronic species the ionic radii (Å) of
N3–, Ne and Al+3 are respectively given by -

Correct orders of Ist I.P. are -
(i) Li < B < Be < C
(ii) O < N < F
(iii) Be < N < Ne

The maximum tendency to form unipositive ion
is for the elment with the electronic configuration-

The second ionisation potentials in electron volts
of oxygen and fluorine atoms are respectively
given by -

A sudden large jump between the values of 2nd
and 3rd IP of an element would be associated
with the electronic configuration-

The correct order of stability of Al+

, Al+2, Al+3 is-

The ionization energy of sodium is 495 kJ mol–1
.
How much energy is needed to convert atoms
persent in 2.3 mg of sodium into sodium ions -

Ionisation energy increases in the order -

Mg forms Mg(II) because of

IP1
and IP2
of Mg are 178 and 348 K.cal mol–1
.
The enthalpy required for the reqction
Mg  Mg2+ + 2e–
is -

Highest ionisation potential in a period is shown
by -