Question
Question: Eka-Boron was the name given by Mendeleev to the element similar to ……… in properties. \( A.{\...
Eka-Boron was the name given by Mendeleev to the element similar to ……… in properties.
A. Scandium B. Silicon C. Aluminium D. Boron
Solution
Hint- In order to solve this question, firstly we will understand the concept of Eka-boron given by Mendeleev. Then we will compare all the concepts given as options to get the required answer.
Complete answer:
Dmitri Mendeleev published a table of the chemical elements in 1869 supported properties that appeared with some regularity as he laid out the weather from lightest to heaviest. When Mendeleev proposed his table , he noted gaps within the table and predicted that unknown elements existed with properties appropriate to fill those gaps. He named them eka-boron, eka-aluminum and eka-silicon, with respective atomic masses of 44, 68 and 72.
The four predicted elements lighter than the rare-earth elements-eka-boron, eka-aluminum, eka-manganese, eka-silicon proved to be good predictors of the properties of scandium, gallium, technetium, germanium respectively, each of which fill the spot within the table assigned by Mendeleev.
Scandium-oxide was isolated in late 1879 when Nilson recognized the correspondence. Mendeleev predicted that atomic mass of 44 for eka-boron in 1871, while scandium had an atomic mass of 44.955.
Eka-boron was the name given by Mendeleev to the predicted element (scandium) lying below boron in the periodic table.
Silicon is an element with the symbol Si and atomic number 14. It is a tough , brittle crystalline solid with a blue-grey metallic lustre, and is tetravalent.
Aluminium is a chemical element with the symbol AI and atomic number is 13. It is a silvery, white, soft and non-magnetic in the boron group.
Boron is a mineral found in food and environment. People take boron supplements as medicine.
Therefore, we conclude that Eka-Boron was the name given by Mendeleev to the element similar to Scandium.
Hence, option A is right.
Note- While solving this question, we must know that Mendeleev proposed his periodic table, he noted gaps in the table and predicted four unknown elements (Eka-boron, Eka-aluminum, Eka-manganese, Eka-silicon) existed with properties appropriate to fill those gaps.