Out of the following the pair which is isoelectronic and isostructural is
SO3,NO3-
ClO3-, CO2-3
CO22-, SO3
NO-3, CO2-3
The pair in which ionization energy of the first species is less than that of the second is
N,P
N,N-
Be+, Be
S,P
If 'x' denotes the number of valence electrons of an element, its valency equals
X
x-8
8-x
either (a) or (c)
Among Mg, Mg2+, Al, Al3+ the largest and smallest species respectively are
Mg & Al
Mg2+ &Al
Mg &Al3+
Mg2+&Al3+
Of the following pairs, the one containing a metalloid element is
F&Cl
Ca &Mg
As & Sb
Na & K
The element of atomic number 8 is closest in chemical properties of the elements having atomic number
7
9
18
16
The species having highest ionization potential is
Ne
Mg+
Li+
Al+
The higher oxide of an element (E) has the formula EO3. Its hydride contains 2.47% hydrogen, the element is
Si
S
Se
Te
An element belongs to fourth period of p- block elements. It has 5 electrons in its outermost shell. Then, the correct statement regarding the element is
It belongs to group 15 and has 5 unpaired electrons.
It belongs to group 15 and has no unpaired electrons.
It belongs to group 14 and has 3 unpaired electrons.
It belongs to group 15 and has 3 unpaired electrons.
On Pauling electronegativity scale, the element nearest to fluorine is
N
O
Cl
