Periodic Classification of Elements Periodic Classification of Elements Periodic Classification of Elements

Q.1. Why is it necessary to classify the elements in a periodic table?

Q.2. Who was the first to classify elements into metals and non-metals?

Q. Who gave the Law of Triads for classification of elements?

Q.4. Which of the following sets of elements follow Dobereiner’s Law of Triads?

Q.5 (English Translation): Which of the following groups of elements does not follow Döbereiner’s Law of Triads?

Q.6  Consider the statements—

1. The German chemist Johann Döbereiner gave the Law of Triads for classifying elements.
2. In a triad, the atomic mass of the middle element is equal to the sum of the atomic masses of the other two elements.

Options:

Q.7 (English Translation): Who did the very first classification of elements?

Who proposed the Octave Rule (Law of Octaves) for the classification of elements?

Q.9 “If the elements are arranged in the order of their increasing atomic masses, then starting from any element, the properties of the 8th element are similar to the first one.” This rule is —

10 Consider the following statements—

1. In his Law of Octaves, Newlands left vacant spaces for many unknown elements whose discovery in the future was certain.
2. Newlands assumed that there are only 56 elements in nature, and no new elements would be discovered in the future.

Which of the above statements is/are correct?

11.X, Y, and Z are triad elements. If the atomic mass of X is 8 and of Z is 10, then what is the atomic mass of Y?

12.M and N are two elements with similar properties that follow Newlands’ Law of Octaves. How many elements are there between M and N?

13.Consider the following statements—

1. Döbereiner’s Law of Triads and Newlands’ Law of Octaves establish a relationship between the atomic mass of elements and their properties.
2. Based on the Law of Triads and the Law of Octaves, it is not possible to classify all elements completely.

Which of the above statements is/are correct?

14.“The physical and chemical properties of elements are a periodic function of their atomic masses.” Who proposed this rule for the classification of elements?

15.According to Mendeleev’s Periodic Law, the properties of elements are a periodic function of their ………

Who is called the father of the Periodic Table?

17  Consider the following statements—

1. The Periodic Table was first constructed by Mendeleev.

2. The modern Periodic Table is a modified form of Mendeleev’s Periodic Table.

Which of the above statements is/are correct?

Q.18. On what basis did Mendeleev classify elements in his Periodic Table?

19.Which scientist arranged elements in the Periodic Table in the increasing order of atomic mass?

In which year was Mendeleev’s Periodic Table first published?

In which year did Mendeleev, the father of the Periodic Table, pass away?

18.In the year 1817, ---- tried to arrange elements with similar properties into groups.

In which year did Newlands propose his Law of Octaves?

24. What are the vertical columns of the Periodic Table called?

25 What are the horizontal rows of the Periodic Table called?

How many periods are there in Mendeleev’s Periodic Table?

Q.27  Consider the following statements—

29. The element of which group is called a “coinage metal”?

30. In Mendeleev’s periodic table, inert gases are placed in which group?

31. Which group in Mendeleev’s periodic table did he not divide into subgroups?

32. How many elements were known at the time of Mendeleev?

33. Mendeleev’s periodic law predicted the existence of some elements, which were later discovered. Which of the following elements is one of them?

34. Which element was later placed in the vacant space left by Mendeleev in the periodic table?

35. Mendeleev’s eka-aluminium can form which type of oxide? 

36. In Mendeleev’s periodic table, transition elements are located in which group?

37. Consider the following statements:

1. All elements in a group of Mendeleev’s periodic table have similar chemical properties.
2. All elements in a period of Mendeleev’s periodic table have similar chemical properties.

Which of the above statements is/are correct?

38.Mendeleev, in his periodic table, predicted three elements as eka-boron, eka-aluminium, and eka-silicon. What were the names of these elements when they were discovered?

39. Which anomalies are found in Mendeleev’s periodic table?

40. Which element could Mendeleev’s periodic table not place in its proper position?

Which Russian chemist stated that the properties of elements are a periodic function of their atomic masses?

42. Which of the following is a fundamental property of an element?

43. Consider the statement:
"Atomic number, not atomic mass, is the most fundamental property of an element."

Which scientist made this statement?

44. Who formulated the modern periodic law?

45. On what basis are elements classified in the modern periodic table?

46. Regarding the modern periodic table, which of the following statements is false?

47. In the periodic table, the horizontal rows and vertical columns are called, respectively:

48. According to IUPAC, how many total groups and periods are there in the modern periodic table?

49. Regarding the periodic table, which of the following statements is false?

50. Consider the following statements:

1. All elements in a group have the same number of bonding (valence) electrons in their atoms.
2. All elements in a group have the same number of core electrons in their atoms.

Which of the above statements is/are correct?

51. Alkali metals belong to which group of elements?

52. When elements are arranged in increasing order of atomic number, their properties repeat periodically. What is this repetition of properties called?

53. Elements of groups 3–12 in the periodic table are called:

54. Which of the following is NOT a characteristic of a transition element?

55. Which of the following options is NOT correctly matched?

57. In the periodic table, as we move down a group, the reactivity of metals—

56.Consider the following statements:

1. Moving down a group, the number of electron shells in an atom increases.
2. Moving across a period from left to right, the number of electron shells in an atom remains the same.

Which of the above statements is/are correct?

58. Which of the following is the most reactive metal?

59. Which of the following is the least reactive metal?

61. According to the modern periodic law, which period is incomplete?

62. Which of the following is NOT correct?

63. In a group of the periodic table, the tendency of elements to lose electrons (metallic character) as we move from top to bottom –

64. Which of the following elements will show chemical reactions similar to Mg (Magnesium)?

65.In a group of the periodic table, what happens to the atomic size (atomic radius) as we move from top to bottom?

66. Why does the atomic radius (atomic size) of elements increase as we move down a group in the periodic table?

67. An element X forms a chloride of formula XCl, which is a high-melting solid. In which group of the periodic table will element X be?

68. An element is located in Group 3 and Period 2 of the periodic table. Which of the following properties will it exhibit?

69. Which of the following elements has the smallest atomic radius?

71. Consider the following statements:

1. In a group, the atomic size increases as we move from top to bottom.
2. In a period, the atomic size decreases as we move from left to right.

Which of the above statements is/are correct?

70. Which of the following elements has the largest atomic radius?

72. In the periodic table, isotopes of an element are placed –

73. An element in the periodic table has all its electron shells completely filled. To which group does this element belong?

74. Which of the following statements does NOT apply to elements of the same period in the periodic table?

75. Lanthanide and Actinide elements belong to which group?

76. In Group 15 of the periodic table, which element will have the highest metallic character?

77. The last element of each period in the periodic table is –

78. The first element of any period in the periodic table is –

79. Which of the following pairs of elements have similar chemical properties?

80. In which three groups of the periodic table are most metalloids found?

81. In a group of the periodic table, as we move from top to bottom, the ionization energy of elements –

82. In a period of the periodic table, as we move from left to right, the ionization energy of elements –

83. Which of the following elements has the highest ionization energy?

84. Which of the following is the correct order of ionization energy for the metals?

85. Consider the following statements:

1. In a period, the ionization energy of an alkali metal is minimum, while that of a noble gas is maximum.
2. Compared to metals, non-metals have higher ionization energy.

Which of the above statements is/are correct?

86. The first, second, and third ionization energies of an element are E1, E2​, and E3​ respectively. Which one will have the highest value?

87. In each of the following sets, choose the element with the highest ionization energy:

1. Li, Be, B
2. C, N, O
3. He, H, Ne

88. Energy is always required to remove an electron from an atom. Therefore, the value of ionization energy is always –

90. In a group of the periodic table, as we move from top to bottom, which of the following remains the same?

89. In a period of the periodic table, as we move from left to right, which of the following remains the same?

91. The basis for classifying elements into four blocks – s-block, p-block, d-block, and f-block – is –

92. Elements from Group 13 to Group 18 are called –

93. The elements of the periodic table are divided into four blocks. Helium belongs to which block?

94. In the periodic table, the 14 elements of the 6th period and 14 elements of the 7th period are called respectively –

95. Lanthanide and Actinide elements belong to which block?

96. Transition elements belong to which block?

97. In the periodic table, most radioactive elements are found in which block?

98. The strongly metallic alkali metals and alkaline earth metals belong to which block?

99. For an element, if 10 is added to the total number of its valence electrons, the group number is obtained. Which block does this element belong to?

100. Non-metals are placed under which block?

102. Which of the following elements is the most electronegative?

101. How many elements in the periodic table exist in gaseous state at normal temperature and pressure (NTP)?

103. Which of the following elements has the highest non-metallic character?

104. Consider the following statements:

1. Elements from Ce (Z = 58) to Lu (Z = 71) are called Lanthanides.
2. Lanthanides are also called rare earth elements.
3. Elements from Th (Z = 90) to Lr (Z = 103) are called Actinides.
4. Most Actinide elements are radioactive.

Which of the above statements are correct?

105. Transition metals have incompletely filled –

106. Which of the following pairs of elements are found in liquid state at normal temperature and pressure (NTP)?

107. When elements are arranged in increasing order of atomic number, their properties repeat. The repetition of properties occurs after –

108. Which of the following oxides is the most basic?

110. Elements A, B, C, and D belong to Groups 1, 2, 14, and 15 of the periodic table, respectively. Which of the following pairs can form a covalent bond?

109. An element has the electronic configuration .This element belongs to which block?

111. In the periodic table, two elements are named after the country France. One is Francium. The other element is –

112. Which of the following elements has the highest electron affinity?

113. In the same group of the periodic table, the ionization energy of elements –

114. Regarding the modern periodic table, which statement is false?

115. What is the chemical symbol of the element Curium?

117. How many elements in the periodic table have their symbols represented by a single letter?

118. Which of the following elements has the smallest atomic size?

119. Which of the following elements has the smallest atomic radius?

120. Which of the following is a transition element?

121. From which of the following is it easiest to remove an electron?

122. In the periodic table, which elements have the same number of electrons as K⁺ and Cl⁻?

123. An element X from Group 2 combines with an element Y from Group 16. What will be the formula of the compound formed? 

124. Consider the following statements:

1. The size of a cation is smaller than its corresponding atom.
2. The atomic radius of Na⁺ is smaller than that of Na atom.
3. The size of an anion is larger than its corresponding atom.
4. The atomic radius of Cl⁻ is larger than that of Cl atom.

Which of the above statements are correct?

125. Which of the following elements will form an acidic oxide?

126. An element has atomic number 15. What will be the nature of its oxide?

127. Consider the following statements:

1. Mendeleev’s periodic table did not include isotopes of elements.
2. In the modern periodic table, isotopes are placed in the same position as their element

Which of the above statements are correct?

128. The correct order of increasing atomic radius for the following elements: Na, K, Mg, Rb?

129. In a Cl₂ molecule, the bond length is 198 pm. What is the atomic radius of chlorine?

130. In solid copper, the distance between two adjacent copper atoms is 256 pm. What is the metallic radius of copper?

132. In which group of the periodic table is potassium placed?

133. The outer electronic configuration of s-block elements is –

134. Which of the following pairs of elements are located between atomic numbers 19 and 22?

135. Consider the following statements:

1. Elements with the same electronic configuration have similar properties.
2. The periodicity of elements’ properties is directly related to the periodicity of their electronic configurations.

Which of the above statements are correct?

136. In the modern periodic table, the positions of which two elements are disputed?

137. Which is the lightest metal?

139. According to IUPAC, what will be the symbol and name of the element with atomic number 120?

138. Which is the lightest element?

140. How many elements are there in the fifth period of the modern periodic table?

141. Which is the heaviest metal?

142. According to Mendeleev, the element Eka-aluminium would form which type of oxide?

143. Which of the following is not a periodic property, i.e., it does not show a trend across a period in the periodic table?

144. According to Lothar Meyer, the chemical properties of elements are a periodic function of –

145. Consider the following statements:

1. The chemical reactivity of metals increases down a group in the periodic table.
2. The chemical reactivity of non-metals decreases down a group in the periodic table.

Which of the above statements are correct?

146. In solid copper, if the interatomic distance between two nearest copper atoms is 256 pm, then what will be the metallic radius of copper?