Which of the following is correct?
The number of electrons present in the valence shell of S in SF6 is 12.
The rates of ionic reactions are very slow
According to VSEPR theory, SnCl2 is a linear molecule.
The correct order of ability to form ionic compounds among Na+, Mg2+ and Al3+ is Al3+ >Mg2+ >Na+.
Observe the following statements :
I. The physical and chemical properties of elements are periodic functions of their electronic configuration.
II. Electronegativity of fluorine is less than the electronegativity of chlorine.
III. Electropositive nature decreases from top to bottom in a group.
The correct answer is :
I, II and III are correct
only I is correct
only I and II is correct
only II and III are correct
The atomic numbers of elements A, B, C and D are Z - 1; Z; Z + 1 and Z + 2, respectively. If 'B' is a noble gas, choose the correct answers from the following statements-
1) 'A' has higher electron affinity.
(2) 'C' exists in +2 oxidation state.
(3) 'D' is an alkaline earth metal.
(1) and (2)
(2) and (3)
(1) and (3)
(1), (2) and (3)
C.
(1) and (3)
Given,
Atomic number of element B = Z ( Noble gas; Belongs to zero group)
Atomic number of element A = Z - 1 (i.e. halogens)
Atomic number of element C = Z + 1 (i.e. Group IA)
Atomic number of element D = Z + 2 (i.e. Group IIA)
Since, element B is a noble gas.
Element A must be a halogen i.e. have highest electron affinity and
Element C must be an alkali metal and exists in +1 oxidation state and
Element D must be an alkaline earth metal with +2 oxidation state.
The correct order of reducing abilities of hydrides of V group elements is
NH3 < PH3 < AsH3 < SbH3 < BiH3
NH3 > PH3 > AsH3 > SbH3 > BiH3
NH3 < PH3 > AsH3 > SbH3 > BiH3
SbH3 > BiH3 > AsH3 > NH3 > PH3
A radioactive substance 88X228 (IIA) emit 3α and 3β particles to form "Y". To which group of long form of the periodic table does "Y" belong ?
IVA
VA
VIA
VIIA
Which one of the following order is correct for the first ionisation energies of the elements?
B < Be < N < O
Be < B < N < O
B < Be < O < N
B < O < Be < N
Which one of the following is correct order of second ionisation potential of Na, Ne, Mg and Al?
Al < Na < Mg < Ne
Ne < Al < Na < Mg
Mg < Al < Ne < Na
Na < Mg < Ne < Al
Identify the most acidic oxide among the following oxides based on their reaction.
SO3
P4O10
Cl2O7
N2O5
Match the following:
List - I | List - II |
A. Rubidium | 1. Germanium |
B. Platinum | 2. Radioactive chalcogen |
C. Eka-silicon | 3. s-block element |
D. Polonium | 4. Atomic number 78 |
A - 4; B - 3; C - 2; D - 1
A - 3; B - 4; C - 1; D - 2
A - 2; B - 1; C - 4; D - 3
A - 4; B - 3; C - 1; D - 2