Periodic Classification of Elements Class 10 MCQ
1.The tenth element in the Newland’s periodic classification resembles with :
(A) first
(B) third
(C) fourth
(D) ninth
Ans. (B)
Sol. Third (7 + 3)
2. If the first and third members of a Dobereiner triad are Phosphorus and Antimony, the second member of this triad is:
(A) Arsenic
(B) Sulphur
(C) Iodine
(D) Calcium
Ans. (A)
Sol. P, As, Sb – Dobereiner triad
3. Dobereiner, in 1829, pointed out that when elements are arranged in the order of increasing relative atomic masses, in a triad, the relative atomic mass of the middle element was approximately equal to the mean of the relative atomic masses of the first and third elements. Name the element which is in between the elements Calcium and Barium :
(A) Beryllium
(B) Magnesium
(C) Strontium
(D) Iodine
Ans. (C)
Sol. Ca, Sr, Ba – Dobereiner triad
4. Which of the following statement is not true regarding Dobereiner Law of Triads :
(A) All the elements of the triad had similar chemical properties
(B) Lithium, sodium and potassium form a triad
(C) In a triad, the atomic number of the middle element is equal to the arithmetic mean of the atomic numbers of the first and last element of the triad
(D) None of the above
Ans. (C)
Sol. In traid mass of middle element is equal to arithmetic mean of remaining elements.
5. “The law of octaves” was enunciated by :
(A) Lothar Meyer
(B) Mendeleev
(C) Dobereiner
(D) Newlands
Ans. (D)
Sol. The law of octaves given by newlands
6. Elements A, B and C form a Dobereiner’s triad. If the atomic mass of element A is 7 and that of element C is 39, then what is the atomic mass of element B ?
(A) 23
(B) 32
(C) 46
(D) 22
Ans. (A)
Sol. Mass B = \frac{{7 + 39}}{2} = \frac{{46}}{2} = 23
7. Which of the following represents a Dobereiner’s triad ?
(A) Na, Cl, Ca
(B) Cl, Br, I
(C) Li, Br, Sr
(D) K, I, Ba
Ans. (B)
Sol. Cl, Br, I – Dobereiner’s triad
8. The third member of the Dobereiner triad consisting of Lithium and Sodium is :
(A) Potassium
(B) Hydrogen
(C) Boron
(D) Barium
Ans. (A)
Sol. Li, Na, K – Dobereiner traid
9. X and Y are two elements having similar properties which obey Newland’s Law of Octaves. The minimum and the maximum number of elements in between X and Y respectively are :
(A) 6 and 8
(B) 7 and 15
(C) 8 and 14
(D) 6 and 13
Ans. (D)
Sol. 6 and 13 because after every 8th element chemical property repeats.
10. Which of the following is not a noble gas?:
(A) Radon
(B) Heilum
(C) Xenon
(D) Radium
Ans. (D)
Sol. Noble gas element gas are He, Ne, Ar, Kr. Xe and Rn.
11. Name the Russian chemist who stated that the properties of elements are the periodic function of their atomic masses?
(A) Mendeleev
(B) Markownikov
(C) Zaitzev
(D) Zelinsky
Ans. (A)
Sol. The Russian chemist Mendeleev stated that the properties of elements are the periodic function of their atomic masses.
12. Which of the following is a defect of the Mendeleev’s periodic table?
(A) The position of alkali metals.
(B) The position of transition metals.
(C) The position of isotopes
(D) Position of Halogens
Ans. (C)
Sol. Mendeleev did not give position of isotopes in his periodic table.
13. Mendeleev periodic table had no place for :
(A) Alkali metals
(B) Alkaline earth metals
(C) Halogens
(D) Noble gases
Ans. (D)
Sol. Mendeleev periodic table had no place for Noble gases.
14. Eka–aluminium is named now a days as :
(A) Gallium
(B) Germanium
(C) Strontium
(D) Barium
Ans. (A)
Sol. Gallium = Eka aluminium
15. Which of the following is not a limitation of Mendeleev’s Periodic table?
(A) In some cases, it was found that an element with higher atomic mass was placed before an element with lower atomic mass
(B) The position of hydrogen was not fixed i.e. it could be placed with alkali metals as well as halogens
(C) All the isotopes of an element were placed at separate position in the Mendeleev’s Periodic table
(D) None of the above
Ans. (C)
Sol. All the isotopes were not placed of an element.
16. Mendeleev arranged only about ––––––––––– elements known at that time :
(A) 53
(B) 63
(C) 73
(D) 65
Ans. (B)
Sol. Mendeleev arranged 63 elements.
17. What is the position of sodium in Mendeleev’s periodic table :
(A) I A group
(B) I B group
(C) II A group
(D) II B group
Ans. (A)
Sol. In Mendeleev’s periodic table, Sodium is present in 3rd period and I A group.
18. The two elements for which Mendeleev left blank places in his original periodic table are :
(A) Si, Ti
(B) Ga, Ge
(C) Al, Ga
(D) As, Sb
Ans. (B)
Sol. Mendeleev left blank places for Ga, Ge.
19. Mark the group which has oxygen and sulphur elements in Mendeleev’s periodic table :
(A) I
(B) II
(C) VI
(D) IV
Ans. (C)
Sol. Group which has oxygen and sulphur elements in Mendeleev’s periodic table is VIth group.
20. According to Mendeleev’s periodic law which properties of the elements are the periodic function of their atomic masses:
(A) Physical properties only
(B) Chemical properties only
(C) Physical and chemical properties both
(D) None of these
Ans. (C)
Sol. Physical and chemical properties both are the periodic function of their atomic masses.
21. The elements belonging to second period are called :
(A) Normal elements
(B) Actinides
(C) Transition elements
(D) Lanthanides
Ans. (A)
Sol. Second period elements are known as normal elements.
22. The maximum number of elements in present in 3rd period is :
(A) 8
(B) 18
(C) 32
(D) Between 8 and 18
Ans. (A)
Sol. In 3rd period total 8 elements (from Na to Ar) are present.
23. Alkali metals belong to:
(A) s – block
(B) p – block
(C) d – block
(D) f – block
Ans. (A)
Sol. Alkali metal are s-block elements.
24. Which one is more metallic element :
(A) Na
(B) Mg
(C) AI
(D) Si
Ans. (A)
Sol. Left to right metallic character decreases that’s why Na is more metallic.
25. In the Modern periodic table, which statement is the most correct about a period?
(A) The first element is an alkali metal and the last element is a halogen.
(B) The first element is a noble gas and the last one is an alkali metal.
(C) The first element is an alkali metal and the last element is a noble gas.
(D) None of these.
Ans. (C)
Sol. Ist group – alkali metals.
last 18th group – noble gases.
26. Choose the false statement according to Modern Periodic Table :
(A) All the isotopes of an element belong to the same group of the periodic table.
(B) Metals are present in right side of periodic table.
(C) The atomic number is a fundamental property of an element.
(D) The atomic radius of Li is greater than the atomic radius of Fluorine.
Ans. (B)
Sol. Metals are present in left and middle side of periodic table.
27. The long form of periodic table is based on :
(A) Molecular masses
(B) Atomic masses
(C) Atomic numbers
(D) Mass numbers
Ans. (C)
Sol. The long form of periodic table is based on atomic number/ proton number.
28. How many groups are present in the modern periodic table :
(A) 10
(B) 18
(C) 16
(D) 8
Ans. (B)
Sol. Number of groups present in the modern periodic table are 18.
29. Atomic number as fundamental property was shown by :
(A) Roentgen
(B) Moseley
(C) Mendeleev
(D) Rutherford
Ans. (B)
Sol. Atomic number as fundamental property was shown by Moseley.
30. The number of periods in long form of periodic table is :
(A) 6
(B) 7
(C) 10
(D) 18
Ans. (B)
Sol. The number of periods present in long form of periodic table are 7.
31. Carbon belongs to 2nd period and 14th group, Silicon belongs to 3rd period and group 14th. If atomic number of Carbon is 6, the atomic number of Silicon is :
(A) 7
(B) 14
(C) 24
(D) 16
Ans. (B)
Sol. Second period contain 8 elements so difference of elements between carbon and silicon is 8 so atomic number of silicon is 6 + 8 = 14.
32. The correct sequence of atomic radii is :
(A) Na > Mg > Al > Si
(B) Al > Si > Na > Mg
(C) Si > Al > Mg > Na
(D) Si > Al > Na > Mg
Ans. (A)
Sol. Atomic radii decreases left to right in the periods so correct sequence of atomic radii is Na > Mg > Al > Si.
33. Most abundant non metal on earth crust :
(A) Silicon
(B) Oxygen
(C) Hydrogen
(D) Sulphur
Ans. (B)
Sol. Oxygen is most abundant non metal present on earth crust.
34. Halogens are present in group _________ of modern periodic table :
(A) 17
(B) 16
(C) 15
(D) 18
Ans. (A)
Sol. Group 17 – Halogen group
35. Most non-metallic element among the following is:
(A) Oxygen
(B) Fluorine
(C) Nitrogen
(D) Chlorine
Ans. (B)
Sol. Left to right non-metallic character increases in periods so fluorine is most non-metallic element.
36. Most of inert gases were discovered by :
(A) Mendleev
(B) Newland
(C) Dobereiner
(D) Ramsey and Rayleigh
Ans. (D)
Sol. Most of inert gases were discovered by Ramsey and Rayleigh.
37. Which of the following is the most metallic :
(A) Li
(B) Ca
(C) K
(D) Cl
Ans. (C)
Sol. Among all element K – most metallic.
38. Antimony and Arsenic belongs to the category of :
(A) Metals
(B) Metalloids
(C) Non metals
(D) Minerals
Ans. (B)
Sol. Sb and As – metalloids
39. In the long form of periodic table lanthanides are placed in the :
(A) 2nd period
(B) 5th period
(C) 6th period
(D) 7th period
Ans. (C)
Sol. Lanthanides – 6th period
Actinides – 7th period
40. The element with atomic number 50 belongs to –––––– group and _______ period of modern periodic table respectively :
(A) 4th, 15th
(B) 5th, 14th
(C) 15th, 4th
(D) 14th, 5th
Ans. (D)
Sol. It is Sn(Tin) Period – 5th
Group – 14th
41. Considering the elements B, Al, Mg and K, the correct order of their metallic character is :
(A) B > Al > Mg > K
(B) Al > Mg > B > K
(C) Mg > Al > K > B
(D) K > Mg > Al > B
Ans. (D)
Sol. Metallic character increase when go up to down in group and right to left in period, that’s why K > Mg > Al > B.
42. In going from left to right in a period :
(A) The basic nature of the oxides increase
(B) Acidic nature decreases
(C) The basic nature of the oxide decreases
(D) No gradation in the nature of oxides is observed
Ans. (C)
Sol. Basic nature of oxides decreases and acidic nature of oxides increases in a period left to right.
43. The element with the highest ionisation potential is :
(A) Oxygen
(B) Nitrogen
(C) Carbon
(D) Boron
Ans. (B)
Sol. Order of ionisation energy is B < C < O < N
44. The most electronegative element is :
(A) Nitrogen
(B) Fluorine
(C) Oxygen
(D) Chlorine
Ans. (B)
Sol. The most electronegative element is F.
45. Which of the following elements has the maximum electron affinity :
(A) Oxygen
(B) Chlorine
(C) Fluorine
(D) Nitrogen
Ans. (B)
Sol. Elements has the maximum electron affinity is Cl.
46. Which of the following elements has the lowest ionisation potential :
(A) Na
(B) K
(C) Mg
(D) Al
Ans. (A)
Sol. Ionisation energy decrease when go up to down in group and left to right in period increase, Na (in 3rd period)
47. Arrange the following halogens in the increasing order of their reactivity : F2, Cl2, Br2, I2
(A) F2, Cl2, Br2, I2
(B) I2, Br2, Cl2, F2
(C) Cl2, F2, Br2, I2
(D) I2, Br2, F2, Cl2
Ans. (A)
Sol. Increasing order of reactivity is F2 > Cl2 > Br2 > I2.
48. Observe the following elements of the second period as given below :
Li, Be, B, C, N, O, F and Ne
What is common in them :
(A) Electronic configuration
(B) Valence shells
(C) Valence electrons
(D) All of these
Ans. (B)
Sol. In period, total number shell of different-different element do not change.
49. Examine the following elements of the third period of Modern periodic table :
Na, Mg, Al, Si, P, S, Cl
How will tendency to lose electrons vary in given series :
(A) Increases
(B) Decreases
(C) Increases then decreases
(D) Decreases then increases
Ans. (B)
Sol. In periodic table on moving left to right electron loosing property decrease.
50. Considering the elements B, C, N, F and Si, the correct order of their non metallic character is:
(A) B > C > Si > N >F
(B) Si > C > B > N > F
(C) F > N > C > B > Si
(D) F > N > C > Si > B
Ans. (D)
Sol. Non-metallic character decrease when go up to down in group and increase left to right in period
F > N > C > Si > B.