In which of the following arrangements the order is NOT according to the property indicated against it?
Al3+ < Mg2+ < Na+ < F- Increasing ionic size
B < C < N < O Increasing first ionization enthalpy
I < Br < F < Cl Increasing electron gain enthalpy (with negative sign)
I < Br < F < Cl Increasing electron gain enthalpy (with negative sign)
The decreasing order of basic character of K2O, BaO, CaO and MgO is
K2O > BaO > CaO > MgO
K2O > CaO > BaO > MgO
MgO > BaO > CaO > K2O
MgO > CaO > BaO > K2O
The increasing order of the first ionization enthalpies of the elements B, P, S and F (lowest first) is
F < S < P < B
P < S < B < F
B < P < S < F
B < P < S < F
Which of the following statements in relation to the hydrogen atom is correct?
3s orbital is lower in energy than 3p orbital
3p orbital is lower in energy than 3d orbital
3s and 3p orbitals are of lower energy than 3d orbital
3s and 3p orbitals are of lower energy than 3d orbital
Following statements regarding the periodic trends of chemical reactivity of the alkali metals and the halogens are given. Which of these statements gives the correct picture?
The reactivity decreases in the alkali metals but increases in the halogens with increase in atomic number down the group
In both the alkali metals and the halogens the chemical reactivity decreases with increase in atomic number down the group
Chemical reactivity increases with increase in atomic number down the group in both the alkali metals and halogens
Chemical reactivity increases with increase in atomic number down the group in both the alkali metals and halogens
The charge/size ratio of a cation determines its polarizing power. Which one of the following sequences represents the increasing order of the polarizing power of the cationic species, K+, Ca2+, Mg2+, Be2+?
Mg2+ < Be2+ < K+ < Ca2+
Be2+ < K+ < Ca2+ < Mg2+
K+ < Ca2+ < Mg2+ < Be2+
K+ < Ca2+ < Mg2+ < Be2+
In a multi-electron atom, which of the following orbitals described by the three quantum numbers will have the same energy in the absence of magnetic acid and electric fields?
(a) n = 1, l = 0, m = 0
(b) n = 2, l = 0, m = 0
(c) n = 2, l = 1, m = 1
(d) n = 3, l = 2, m = 1
(e) n = 3, l = 2, m = 0
(a) and (b)
(b) and (c)
(c) and (d)
(c) and (d)