CBSE Class 11 Chemistry Classification Of Elements And Periodicity Worksheet

PERIODIC TABLE

Question. The atomic number of an element x is 12. The element left to it and right to it in same period of periodic table are -
(A) Be, Ca
(B) Al, P
(C) K, Li
(D) Na, Al
Answer. D

Question. An element has atomic number 13. Which of the following statements concerning this element is wrong?
(A) the atom has 13 protons
(B) the element is placed in the third period of the periodic table
(C) the element is placed in group IV in the periodic table.
(D) the formula of its oxide is X₂O₃
Answer. C

Question. Which of the following represents the electronic configuration of d-block elements ?
(A) (n–1)s² nd1–10
(B) (n–1)d^1–10ns^1-2
(C) (n–1)d^1–10 ns²p⁴
(D) (n–1)p⁴ns²
Answer. B

Question. Transition metals are characterised by the properties except :
(A) variable valency
(B) form coloured compounds
(C) high melting and boiling points
(D) no tendency to form complexes
Answer. D

Question. Which of the following is a noble gas ?
(A) He
(B) N₂
(C) H₂
(D) O₂
Answer. A

Question. Which one of the following belongs to representative group of elements in the periodic table ?
(A) Lanthanum
(B) Argon
(C) Chromium
(D) Aluminium
Answer. D

Question. Which of the following pairs of elements does not belong to same group ?
(A) Cl, Br
(B) N, P
(C) Mg, Ca
(D) Al, Si
Answer. D

Question. Which of the following statement is False?
(A) In modern periodic table each block contains a number of columns equal to the number of electrons than can occupy that sub-shell.
(B) The greatest increase in ionization enthalpy is experienced on removal of electron from core noble gas configuration.
(C) In 13th group, values of electronegativity increases regularly from top to bottom
(D) Anything that influences the valence electrons will affect the chemistry of the element and the valence shell is not affected by nuclear mass
Answer. C

Question. The element with atomic number 56 is likely to have the same outer shell configuration as the element with atomic number :
(A) 12
(B) 18
(C) 14
(D) 30
Answer. A

Question. If aufbau rule is not followed, 20Ca will be placed in _________ block.
(A) s-
(B) p-
(C) d-
(D) f-
Answer. C

Question. What is the position of the element in the periodic table satisfying the electronic configuration (n – 1) d¹ ns² for n = 4
(A) 3rd period and 3rd group
(B) 4th period and 4th group
(C) 3rd period and 2nd group
(D) 4th period and 3rd group
Answer. D

Question. Hydrogen has the tendency to gain one electron to acquire helium configuration. In this respect it resembles -
(A) alkali metals
(B) carbon
(C) alkaline earth metals
(D) halogens
Answer. D

Question. Elements in the same vertical group of the periodic table have generally the same -
(A) atomic number
(B) electronic configuration
(C) atomic mass
(D) number of electrons in the outermost shell of their atoms
Answer. D

Question. Elements A, B, C, D and E having the following electronic configuration -
(i) 1s², 2s², 2p¹
(ii) 1s², 2s², 2p⁶, 3s², 3p¹
(iii) 1s², 2s², 2p⁶, 3s², 3p³
(iv) 1s², 2s², 2p⁶, 3s², 3p⁵
(v) 1s², 2s², 2p⁶, 3s², 3p⁶
Electronic configurations belonging to same group are -
(A) (i) and (iii)
(B) (i) and (iv)
(C) (i) and (ii)
(D) (i) and (v)
Answer. C

Question. The most electropositive element in periodic table is:
(A) F
(B) Na
(C) K
(D) Cs
Answer. D

Question. Which of the following statement is false ?
(A) The metallic character on moving from left to right in a period, decreases.
(B) Metallic character increases on going down a group.
(C) atomic radius decreases on moving from left to right in a period.
(D) The chemical reactivity of metals, on moving from left to right in a period increases.
Answer. D

Question. The ionisation energy of isotopes of an element will be -
(A) same
(B) different
(C) dependent on atomic masses
(D) dependent on the number of neutrons present in the nucleus
Answer. A

Question. Which of the following is the increasing order of electron affinity of halogens ?
(A) Cl < Br < I < F
(B) I < Br < F < Cl
(C) F < Cl < Br < I
(D) Br < F < I < Cl
Answer. B

Question. In which of the following arrangements, the order is not according to the property indicated against it ?
(A) Al³⁺ < Mg²⁺ < Na⁺ < F^– - Increasing ionic size
(B) B < C < N < O - Increasing first ionisation energy
(C) I < Br < F < Cl - Increasing electron affinity
(D) Li < Na < K < Rb - Increasing metallic radius
Answer. B

Question. The most basic oxide among MnO, Mn₂O₃, MnO₂ and Mn₂O₇ is -
(A) MnO
(B) MnO₂
(C) Mn₂O₃
(D) Mn₂O₇
Answer. A

Question. The first (IE₁) and second (IE₂) ionisation energies (KJmol^–1) of a few elements are shown below :
      IE₁         IE₂
(i) 2372     5251
(ii) 520      7300
(iii) 900     1760
(iv) 1680   3380
Which of the above elements is likely to be a noble gas ?
(A) (i)
(B) (ii)
(C) (iii)
(D) (iv)
Answer. A

Question. The incorrect statement among the following is :
(A) the first ionisation potential of Al is less than first ionisation potential of Mg
(B) the second ionisation potential of Mg is greater than the second ionisation potential of Na
(C) the first ionisation potential of Na is less than the first ionisation potential of Mg
(D) the third ionisation potential of Mg is greater than third ionisation potential of Al
Answer. B

Question. The element with highest electronegativity is -
(A) carbon
(B) chlorine
(C) fluorine
(D) oxygen
Answer. C

Question. Elements of which group form anions most readily ?
(A) Oxygen family
(B) Nitrogen family
(C) Halogens
(D) Alkali metals
Answer. C

Question. The process(es) requiring the absorption of energy is/are :
(A) Cl – Cl^–
(B) S → S^2–
(C) Ar → Ar^–
(D) Both (B) and (C)
Answer. D

Question. Which of the following is smallest in size -
(A) O^2–
(B) C^4–
(C) F^–
(D) N^3–
Answer. C

Question. The correct order of radii is:
(A) Li < Be <Mg
(B) Be⁺² < Li⁺ < H^–
(C) Mn³⁺ < Mn²⁺ < Mn⁺⁷
(D) K⁺ >Cl^– > S^2–
Answer. B

Question. Which of the following is the incorrect statement ?
(A) The first ionisation potential of Al is lesser than the first ionisation potential of Mg
(B) Atomic radius of Li is less than that of Cs
(C) The formation of S²- from S^– is an endothermic process
(D) All of these are incorrect statements.
Answer. D

Question. The first ionisation energy of Na, Mg, Al and Si are in the order of :
(A) Na < Mg > Al < Si
(B) Na > Mg > Al > Si
(C) Na < Mg < Al > Si
(D) Na > Mg > Al < Si
Answer. A

Question. Which one of the following statements is correct ?
(A) The elements like F, Cl, Br etc having high values of electron affinity act as strong oxidising agent.
(B) The elements having low values of ionisation energies act as strong reducing agent.
(C) The formation of Be–(g) from Be(g) is an endothermic process
(D) All of these
Answer. B

Question. For the element 'A', the first ionisation energy will be numerically equal to :
(A) EA of A⁺
(B) EA of A²⁺
(C) IE of A²⁺
(D) None of these
Answer. A

Question. Which of the following statements is not correct regarding hydrogen :
(A) It resembles halogens in some properties.
(B) It resembles alkali metals in some properties.
(C) It can be placed in 17th group of Modern periodic table.
(D) It cannot be placed in 1st group of Modern periodic table.
Answer. D

Question. Atomic number of Ag is 47. In the same group, the atomic numbers of elements placed above and below Ag in Long form of periodic table will be :
(A) 29, 65
(B) 39, 79
(C) 29, 79
(D) 39, 65
Answer. C

Question. 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 :
(A) s > p > d > f
(B) f > d > p > s
(C) p < d < s > f
(D) f > p > s > d
Answer. A

Question. Which of the following is generally true regarding effective nuclear charge (Zeff) :
(A) It increases on moving left to right in a period.
(B) It remains almost constant on moving top to bottom in a group.
(C) For isoelectronic species, as Z increases, Zeff decreases.
(D) Both (A) and (B).
Answer. D

Question. Among following species which of them have maximum Zeff
(A) Sn
(B) Sn⁴⁺
(C) In
(D) In⁺
Answer. B

Question. From the given set of species, point out the species from each set having highest Zeff.
(a) O^2–, F^–, Na⁺
(b) Li, Be, Na
(c) He, Li⁺, H^–
        a     b    c
(A) Na⁺  Be  Li⁺
(B) O^2–  Li    H^–
(C) F^–    Na  He
(D) Na⁺  Be  He
Answer. A

Question. Select correct statement about radius of an atom :
(A) Values of Vander waal's radii are larger than those of covalent radii because the Vander waal's forces are much weaker than the forces operating between atoms in a covalently bonded molecule.
(B) The metallic radii are smaller than the Vander waal's radii, since the bonding forces in the metallic crystal lattice are much stronger than the Vander waal's forces.
(C) Both (A) & (B)
(D) None of these
Answer. C

Question. Match the correct atomic radius with the element :
S.No.   Element   Code   Atomic radius (pm)
(i)        Be           (p)        74
(ii)       C             (q)        88
(iii)      O             (r)        111
(iv)      B             (s)        77
(v)       N             (t)        66
(A) (i) – r, (ii) – q, (iii) – t, (iv) – s, (v) – p
(B) (i) – t, (ii) – s, (iii) – r, (iv) – p, (v) – q
(C) (i) – r, (ii) – s, (iii) – t, (iv) – q, (v) – p
(D) (i) – t, (ii) – p, (iii) – r, (iv) – s, (v) – q
Answer. C

Question. Choose the correct order of atomic radii of Fluorine and Neon (in pm) out of the options given below :
(A) 72, 160
(B) 160, 160
(C) 72, 72
(D) 160, 72
Answer. A

Question. The size of isoelectronic species O^-2 , F^– and Na⁺ is affected by :
(A) nuclear charge (Z)
(B) valence principal quantum number (n)
(C) electron-electron interaction in the outer orbitals
(D) none of the factors because their size is the same.
Answer. A

Question.. Which of the following order of atomic / ionic radius is not correct ?
(A) F < Cl < Br < I
(B) Y³⁺ > Sr²⁺ > Rb⁺
(C) Nb ≈ Ta
(D) Li > Be > B
Answer. B

Question. Which one of the following statements is incorrect in relation to ionisation enthalpy ?
(A) Ionization enthalpy increases for each successive electron.
(B) The greatest increase in ionization enthalpy is experienced on removal of electron from core of noble gas configuration.
(C) End of valence electrons is marked by a big jump in ionization enthalpy.
(D) Removal of electron from orbitals bearing lower n value is easier than from orbitals having higher n value.
Answer. D

Question. The first ionisation enthalpies (in eV) of N & O are respectively given by :
(A) 14.6, 13.6
(B) 13.6, 14.6
(C) 13.6, 13.6
(D) 14.6, 14.6
Answer. A

Question. Among halogens, the correct order of amount of energy released in electron gain (electron gain enthalpy) is:
(A) F > Cl > Br > I
(B) F < Cl < Br < I
(C) F < Cl > Br > I
(D) Cl > Br > F > I
Answer. C

Question. Which of the following will have the most negative electron gain enthalpy and which the least negative ?
F, P, S, Cl.
(A) P, Cl
(B) Cl, F
(C) Cl, S
(D) Cl, P
Answer. D