Which of the following is not a Dobereiner triad ?
Li, Na, K
Cl, Br, I
Fe, Co, Ni
Ca, Sr, Ba
Chloride of an element 'A' gives neutral solution in water. In the periodic table, the element 'A' belongs to __________
First transition series
Fifth group
Third group
First group
Out of the following ________ is not isoelectronic
Mg2+
Cl-
Na+
O2-
Of the following pairs, the one containing a metalloid element is _________
F&Cl
Ca &Mg
As & Sb
Na & K
The decreasing order of the second ionization potential of K, Ca and Ba is
K > Ca > Ba
Ca > Ba > K
Ba > K> Ca
K > Ba > Ca
In a given period, the alkali metals have _________
lowest ionisation energy
smallest atomic size
highest electron affinity
lowest density
Noble gases are group of elements which exhibit very
Minimum electronegativity
Low chemical activity
High chemical activity
High diamagnetic properties
The element which forms an amphoteric oxide is
Barium
Calcium
Chlorine
Beryllium
Electron affinity depends on
Atomic size
Nuclear charge
Atomic number
Both atomic size and nuclear charge
On descending a group in the periodic table
Metallic character of elements increases
Electro negativity of elements increases
Ionization energy of elements increases
Size of elements decreases
