Which of the following metal is not placed in eighth group of Mendeleev periodic table?
Which of the following metal is not placed in eighth group of Mendeleev periodic table?
The correct option is B Na
Mendeleev's periodic table
Mendeleev arranged the then discovered elements in the increasing order of their atomic weights to devise the Mendeleev's periodic table. His law states that the properties of elements are a periodic function of their atomic weights. He also left out gaps in periodic table for undiscovered elements and predicted their properties based on the discovered elements. He arranged the elements into groups which have elements with similar properties. Mendeleev's periodic table contains 8 groups.
Explanations for wrong answers
(A) Iron (Fe) belonged to the eighth group in Mendeleev's periodic table. Therefore option (A) is incorrect.
(C) Platinum (Pt) belonged to the eighth group in Mendeleev's periodic table. Therefore, option (C) is incorrect.
(D) Nickel (Ni) belonged to the eighth group in Mendeleev's periodic table. Therefore, option (D) is incorrect.
Explanation for correct answer
(B) Sodium (Na) belonged to the first group in Mendeleev's periodic table with other elements with similar properties like Lithium (Li), Rubidium (Rb), Potassium (K). The elements like Copper (Cu), Silver (Ag) etc. were also in the first group in Mendeleev's periodic table.
The correct option is (B) Na.
Na
Mendeleev's periodic table
Mendeleev arranged the then discovered elements in the increasing order of their atomic weights to devise the Mendeleev's periodic table. His law states that the properties of elements are a periodic function of their atomic weights. He also left out gaps in periodic table for undiscovered elements and predicted their properties based on the discovered elements. He arranged the elements into groups which have elements with similar properties. Mendeleev's periodic table contains 8 groups.
Explanations for wrong answers
(A) Iron (Fe) belonged to the eighth group in Mendeleev's periodic table. Therefore option (A) is incorrect.
(C) Platinum (Pt) belonged to the eighth group in Mendeleev's periodic table. Therefore, option (C) is incorrect.
(D) Nickel (Ni) belonged to the eighth group in Mendeleev's periodic table. Therefore, option (D) is incorrect.
Explanation for correct answer
(B) Sodium (Na) belonged to the first group in Mendeleev's periodic table with other elements with similar properties like Lithium (Li), Rubidium (Rb), Potassium (K). The elements like Copper (Cu), Silver (Ag) etc. were also in the first group in Mendeleev's periodic table.
The correct option is (B) Na.
