Classification of Elements and Periodicity in Properties MCQ's.

Classification of Elements and Periodicity in Properties.

Multiple Choice Questions

  

 

1. According to Periodic Law of elements, the variation in properties of elements is related to their
   1.   nuclear neutron-proton number ratios
   2.   atomic masses
   3.   atomic numbers
   4.   nuclear masses
2. The statement that is not correct for periodic classification of elements is:
   1.   The properties of elements are periodic function of their atomic numbers.
   2.   For transition elements, the 3d-orbitals are filled with electrons after 3p-orbitals and before 4s-orbitals.
   3.   Non metallic elements are less in number than metallic elements.
   4.   The first ionization enthalpies of elements generally increase with increase in atomic number as we go along a period.
3. The period number in the long form of the periodic table is equal to
   1.   magnetic quantum number of any element of the period.
   2.   atomic number of any element of the period.
   3.   maximum Azimuthal quantum number of any element of the period.
   4.   maximum Principal quantum number of any element of the period.
4. The elements in which electrons are progressively filled in 4f-orbital are called
   1.   lanthanoids
   2.   actinoids
   3.   transition elements
   4.   halogens
5. Consider the isoelectronic species, Na⁺, Mg²⁺, F^- and O^2-. the correct order of increasing length of their radii is ……..
   1.   F^- < O^2-< Mg²⁺ < Na⁺
   2.   Mg²⁺, Na⁺ < F^- < O^2-
   3.   O^2- < F^- < Na⁺ < Mg²⁺
   4.   O^2- < F^- < Mg²⁺ < Na⁺
6. The first ionization enthalpies of Na, Mg, Al and Si are in the order:
   1.   Na < Mg > Al < Si
   2.   Na > Mg > Al > Si
   3.   Na < Mg < Al < Si
   4.   Na > Mg > Al < Si
7. The order of screening effect of electrons of s, p, d and f orbitals of a given shell of an atom on its outer shell electrons is:
   1.   f > d > p > s
   2.   p < d < s < f
   3.   f > p > s > d
   4.   s > p > d > f
8. The electronic configuration of gadolinium (Atomic number 64) is
   1.   [Xe] 4f³ 5d⁵ 6s²
   2.   [Xe] 4f⁷ 5d² 6s¹
   3.   [Xe] 4f⁷ 5d¹ 6s²
   4.   [Xe] 4f⁸ 5d⁶ 6s²
9. Which of the following statements are correct?
   1.   Helium has the highest first ionization enthalpy
   2.   Chlorine has less negative electron gain enthalpy than fluorine
   3.   In any period, atomic radius of alkali metal is the highest
   4.   None of the above.
10. Which of the following elements can show covalency greater than 4?
    1.   Be
    2.   C
    3.   P
    4.   B
11. Covalent radius of nitrogen is 70 pm. Hence covalent radius of boron is about
    1.   60 pm
    2.   110 pm
    3.   50 pm
    4.   40 pm
12. The general outer electronic configuration of transition metals is
    1.   ns² nd^1-10
    2.   ns² np¹ (n-1)d^1-10
    3.   ns² np⁶ (n-1)d^1-10
    4.   ns^0-2 (n-1)d^1-10
13. Which pair of atomic numbers represents s-block elements?
    1.   4, 12
    2.   7, 15
    3.   6, 12
    4.   9, 17
14. The elements with atomic number 117 if discovered would be placed in
    1.   noble gas family
    2.   alkali family
    3.   halogen family
    4.   alkaline earth family
15. The ionic radius of ‘Cr’ is minimum in which of the following compounds?
    1.   CrF₃
    2.   K₂CrO₄
    3.   CrO₂
    4.   CrCl₃
16. Which of the following transitions involves maximum amount of energy?
    1.   M^- (g) --> M (g)
    2.   M (g) --> M^- (g)
    3.   M⁺ (g) --> M²⁺ (g)
    4.   M²⁺ (g) --> M³⁺ (g)
17. 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?
    1.   Chemical reactivity increases with increase in atomic number down the group in both the alkali metals and halogens.
    2.   The reactivity decreases in the alkali metals but increases in the halogens with increase in atomic number.
    3.   In alkali metals the reactivity increases but in the halogens it decreases with increase in atomic number down the group.
    4.   In both the alkali metals and the halogens, the chemical reactivity decreases with increase in atomic number down the group.
18. In the following, the element with the highest ionization energy is
    1.   [Ne] 3s² 3p¹
    2.   [Ne] 3s² 3p³
    3.   [Ne] 3s² 3p²
    4.   [Ne] 3s² 3p⁴
19. Among the following, the third ionization energy is highest for
    1.   Magnesium
    2.   Boron
    3.   Beryllium
    4.   Aluminium
20. Which of the following represents most electropositive elements?
    1.   [He] 2s¹
    2.   [He] 2s²
    3.   [Xe] 6s²
    4.   [He] 6s¹
21. In a periodic table, the basic character of oxides
    1.   increases from left to right and decreases from top to bottom
    2.   decreases from right to left and increases from top to bottom
    3.   decreases from left to right and increases from top to bottom
    4.   decreases from left to right and increases from bottom to top
22. Which of the following remains unchanged on descending a group in the periodic table
    1.   Valence electrons
    2.   Atomic size
    3.   Density
    4.   Metallic character
23. The diagonal partner of element B is
    1.   Li
    2.   Al
    3.   Mg
    4.   Si
24. In crystals of which of the following ionic compounds, would you expect the maximum distance between centres of cations and anions.
    1.   CsF
    2.   CsI
    3.   LiI
    4.   LiF
25. Periodic properties show a regular gradation on moving from left to right in a period or from top to bottom in a group. Down a group the atomic/ionic radii and metallic character and reducing character increase while ionization enthalpy and electronegativity decrease. Along a period from left to right, atomic/ionic radii and metallic character decrease while ionization enthalpy electronegativity, non metallic character and oxidizing power increase. However, electron gain enthalpy becomes less negative down a group but more negative along a period. In contrast, inert gases have positive electron gain enthalpies which do not show any regular trend.
    
    The outer most electronic configuration of the most electronegative element is
    1.   ns² np³
    2.   ns² np⁴
    3.   ns² np⁵
    4.   ns² np⁶
26. Periodic properties show a regular gradation on moving from left to right in a period or from top to bottom in a group. Down a group the atomic/ionic radii and metallic character and reducing character increase while ionization enthalpy and electronegativity decrease. Along a period from left to right, atomic/ionic radii and metallic character decrease while ionization enthalpy electronegativity, non metallic character and oxidizing power increase. However, electron gain enthalpy becomes less negative down a group but more negative along a period. In contrast, inert gases have positive electron gain enthalpies which do not show any regular trend.
    
    The correct order of second ionization enthalpy in the following is
    1.   F > O > N > C
    2.   O > F > N > C
    3.   O > N > F > C
    4.   C > N > O > F
27. Periodic properties show a regular gradation on moving from left to right in a period or from top to bottom in a group. Down a group the atomic/ionic radii and metallic character and reducing character increase while ionization enthalpy and electronegativity decrease. Along a period from left to right, atomic/ionic radii and metallic character decrease while ionization enthalpy electronegativity, non metallic character and oxidizing power increase. However, electron gain enthalpy becomes less negative down a group but more negative along a period. In contrast, inert gases have positive electron gain enthalpies which do not show any regular trend.
    
    If the ionic radii of K+ and F- are about 0.134 nm each, then expected values of atomic radii of K and F should be respectively:
    1.   0.231 and 0.064 nm
    2.   0.231 and 0.134 nm
    3.   0.064 and 0.231 nm
    4.   0.134 and 0.134 nm
28. Periodic properties show a regular gradation on moving from left to right in a period or from top to bottom in a group. Down a group the atomic/ionic radii and metallic character and reducing character increase while ionization enthalpy and electronegativity decrease. Along a period from left to right, atomic/ionic radii and metallic character decrease while ionization enthalpy electronegativity, non metallic character and oxidizing power increase. However, electron gain enthalpy becomes less negative down a group but more negative along a period. In contrast, inert gases have positive electron gain enthalpies which do not show any regular trend.
    
    Amongst the following elements, the one having the highest ionization enthalpy is:
    1.   [Ne] 3s² 3p¹
    2.   [Ne] 3s² 3p³
    3.   [Ne] 3s² 3p²
    4.   [Ar] 3d¹⁰ 4s² 4p¹