Classification Of Elements And Periodicity CBSE Questions & Answers

Classification Of Elements And Periodicity

This is Chemistry Class 11 Classification of Elements and Periodicity CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
Before the 4p orbital is filled, filling up of 3d orbitals becomes energetically favourable and there are 3d transition series of elements. This starts from scandium (Z = 21) which has the electronic configuration of.
  • A
    \({\text{3}}{{\text{d}}^{\text{1}}}{\text{4}}{{\text{p}}^{\text{2}}}\)
  • B
    \({\text{3}}{{\text{s}}^{\text{1}}}{\text{4}}{{\text{d}}^{\text{2}}}\)
  • C
    \({\text{3}}{{\text{d}}^{\text{1}}}{\text{4}}{{\text{s}}^{\text{2}}}\)
    Correct
  • D
    \({\text{2}}{{\text{d}}^{\text{1}}}{\text{3}}{{\text{s}}^{\text{2}}}\)
2
An s orbital with one ml can accommodate x electrons, a p orbital with three ml y electrons, and a d orbital with five ml z electrons. The correct values of x, y and z are
  • A
    2, 2, 8
  • B
    2, 6, 10
    Correct
  • C
    2, 10, 10
  • D
    2, 8, 8
3
s-Block Elements comprise
  • A
    Group 1 (alkali metals) and Group 2 (alkaline earth metals)
    Correct
  • B
    Group 1 and Group 4
  • C
    Group 3 and Group 2
  • D
    Group 4 (alkali metals) and Group 7 (alkaline earth metals)
4
All the orbitals in the valence shell of the noble gases
  • A
    not completely filled by electrons and the arrangement is not stable
  • B
    not completely filled by electrons and it is very easy to alter this stable arrangement by the addition or removal of electrons
  • C
    completely filled by electrons and it is very easy to remove electrons
  • D
    are completely filled by electrons and it is very difficult to alter this stable arrangement by the addition or removal of electrons
    Correct
5
d-Block Elements are characterized by the
  • A
    filling of inner d orbitals by electrons
    Correct
  • B
    filling of outer d orbitals
  • C
    absence of d orbital electrons
  • D
    inner d orbitals are not filled
6
f block of the Periodic Table consists of
  • A
    halogens (Group 17) and the chalcogens (Group 16)
  • B
    The two rows of elements at the bottom of the Periodic Table, called the Lanthanides, Ce(Z = 58) ñ Lu(Z = 71) and Actinoids
    Correct
  • C
    The first two groups of the periodic table
  • D
    Groups 13 and 14 “Transition Elements”.
7
Metalloids show the properties of
  • A
    properties that are characteristic of both metals and plastics
  • B
    properties that are characteristic of both metals and gases
  • C
    properties that are characteristic of both metals and viscous liquids
  • D
    properties that are characteristic of both metals and nonmetals
    Correct
8
Which of the following statements is false?
  • A
    Alkali metals forms oxides that act as basic anhydrides.
  • B
    Alkali metals have relatively low first ionization energies
  • C
    Alkali metals usually have a +1 oxidation state
  • D
    Alkali metals form covalent bonds with oxygen.
    Correct
9
Ionization enthalpy increases across a period because
  • A
    screening is more effective
  • B
    outermost electrons are held more and more tightly
    Correct
  • C
    shielding is more effective
  • D
    outermost electrons are not held tightly
10
In the periodic table Electronegativity generally
  • A
    decreases across a period from left to right and decreases down a group
  • B
    decreases across a period from left to right and increases down a group
  • C
    increases across a period from left to right and increases down a group
  • D
    increases across a period from left to right and decreases down a group
    Correct
11
Select the species which are iso-electronic (same number of electron) with each other.
  • A
    \({\text{C}}{{\text{l}}^ - }{\text{and R}}{{\text{b}}^ + }\)
  • B
    \({\text{C}}{{\text{l}}^ - }{\text{and C}}{{\text{a}}^{{\text{2}} + }}\).
    Correct
  • C
    \({\text{R}}{{\text{b}}^ + }{\text{and C}}{{\text{a}}^{{\text{2}} + }}\)
  • D
    \({\text{Ne and C}}{{\text{a}}^{{\text{2}} + }}\)
12
Generally, the first ionization energy increases along a period. But there are some exceptions. One which is NOT an exception is ______.
  • A
    N and O
  • B
    Na and Mg
    Correct
  • C
    Be and B
  • D
    Mg and Al
13
The outer electronic configuration of p- Block elements are:
  • A
    \({\text{3}}{{\text{d}}^{{\text{1}}0}}{\text{4}}{{\text{s}}^{\text{2}}}\)
  • B
    \({\text{3}}{{\text{s}}^{\text{2}}}{\text{3}}{{\text{p}}^{\text{6}}}{\text{4}}{{\text{s}}^{\text{2}}}\)
  • C
    \({\text{3}}{{\text{s}}^{\text{2}}}{\text{3}}{{\text{p}}^{\text{4}}}\)
    Correct
  • D
    \({\text{6}}{{\text{s}}^{\text{2}}}{\text{4}}{{\text{f}}^{\text{3}}}\)
14
To which block of elements in the periodic table \({\text{3}}{{\text{d}}^{{\text{1}}0}}{\text{4}}{{\text{s}}^{\text{2}}}\) belongs?
  • A
    p- Block
  • B
    s- Block
  • C
    s- Block
  • D
    d- Block
    Correct
15
The outer electronic configuration of s- Block elements are:
  • A
    \({\text{6}}{{\text{s}}^{\text{2}}}{\text{4}}{{\text{f}}^{\text{3}}}\)
  • B
    \({\text{3}}{{\text{s}}^{\text{2}}}{\text{3}}{{\text{p}}^{\text{4}}}\)
  • C
    \({\text{3}}{{\text{d}}^{{\text{1}}0}}{\text{4}}{{\text{s}}^{\text{2}}}\)
  • D
    \({\text{3}}{{\text{s}}^{\text{2}}}{\text{3}}{{\text{p}}^{\text{6}}}{\text{4}}{{\text{s}}^{\text{2}}}\)
    Correct