Which one of the following is correct order of increase of size ?
Mg <Al< Na+ < F -
Na+ < Al < Mg < F -
Na+ < F - < Al < Mg
Na+ < F - < Mg < Al
The statement that is not correct for the periodic classification of elements is
the properties of the elements are the periodic function of their atomic number
non-metallic elements are lesser in number than metallic elements
the first ionisation energies of elements along a period do not vary in a regular manner with increase in atomic number
for transition elements, the d-subshells are filled with electrons monotonically with increase in atomic numbers
The correct sequence which shows decreasing order of the ionic radii of the elements is
Al3+ > Mg2+ > Na+ > F - > O2-
Na+ > Mg2+ > Al3+ > O2- > F -
Na+ > F - > Mg2+ > O2- > Al3+
O2- > F - > Na+ > Mg2+ > Al3+
Which element was named as Eka-silicon in Mendeleev's classification of elements ?
Germanium
Gallium
Thallium
Selenium
Ionisation potential and electron affinity of fluorine are 17.42 and 3.45 eV respectively. What will be the ratio of electronegativity of fluorine on Mulliken scale and Pauling scale?
2.80 : 1
1.80 : 1
2.40 : 1
4.20 : 1
Based on lattice energy and other considerations which one of the following alkali metal chlorides is expected to have the highest melting point?
RbCl
KCl
NaCl
LiCl
The charge/size ratio of a cation determines its polarising power. Which one of the following sequences represents the increasing order of the polarising power of the cationic species, K+, Ca2+, Mg2+, Be2+?
Mg2+ < Be2+ < K+ < Ca2+
Be2+ < K+ < Ca2+ < Mg2+
K+ < Ca2+ < Mg2+ < Be2+
Ca2+ < Mg2+ < Be2+ < K+
Identify the correct order of solubility in aqueous medium
CuS > ZnS > Na2S
ZnS > Na2S > CuS
Na2S > CuS > ZnS
Na2S > ZnS > CuS
An extra electron is added at the periphery of nitrogen atom in the formation of anion. What will be the ratio of effective nuclear charge of nitrogen atom and nitrogen anion?
2.09 : 1
0.09 : 1
3.09 : 1
1.09 : 1
Which one of the following is smallest in size ?
N3-
O2-
F -
Na+