1

NEET 2017

The element Z = 114 has been discovered recently. It will belong to which of the following family/group and electronic configuration ?
A
Carbon family, [Rn] 5f14 6d10 7s2 7p2
B
Oxygen family, [Rn] 5f14 6d10 7s2 7p4
C
Nitrogen family, [Rn] 5f14 6d10 7s2 7p6
D
Halogen family, [Rn] 5f14 6d10 7s2 7p5

Explanation

The electronic configuration of th element with Z = 114 is [Rn] 5f14 6d10 7s2 7p2. Hence it belongs to the carbon family which has the same outer electronic configuaration.
2

NEET 2016 Phase 1

In which of the following options the order of arrangement does not agree with the variation of property indicated against it ?
A
I < Br < Cl < F (increasing electron gain enthalpy)
B
Li < Na < K < Rb (increasing metallic radius)
C
Al3+ < Mg2+ < Na+ < F$-$ (increasing ionic size)
D
B < C < N < O (increasing first ionisation enthalpy)

Explanation

The correct order of increasing negative electron gain enthalpy is : I < Br < F < Cl and the correct order of increasing first ionisation enthalpy is B < C < O < N.
3

AIPMT 2015 Cancelled Paper

The species Ar, K+ and Ca2+ contain the same number of electrons. In which order do their radii increase ?
A
Ca2+ < K+ < Ar
B
K+ < Ar < Ca2+
C
Ar < K+ < Ca2+
D
Ca2+ < Ar < K+

Explanation

For isoelectronic species, radius of atom decreases with increase in nuclear charge.
4

AIPMT 2014

Which of the following orders of ionic radii is correctly represented ?
A
H$-$ > H$^ \bullet$ > H+
B
Na+ > F$-$ > O2$-$
C
F$-$ > O2$-$ > Na+
D
A$l$3+ > Mg2+ > N3$-$

Explanation

Cation loose electrons are smaller in size than the parent atom, where anions gain electrons are larger in size than the parent atom.

Hence the order is H- > H > H+