Question

The element eka-silicon predicted by Mendeleev is:
(A) $Ge$
(B) $Ga$
(C) $Al$
(D) $Si$

Answer 1

Hint:Among the expectations made by Mendeleev were the presence, and the properties, of a few unfamiliar components. One of these components was the component currently called Germanium; Mendeleev called it "eka-silicon," signifying "past silicon" on his table.

Complete answer:What are Mendeleev's anticipated elements? Dmitri Mendeleev distributed an intermittent table of the substance components in 1869 dependent on properties that showed up with some routineness as he spread out the components from lightest to heaviest. When Mendeleev proposed his occasional table, he noted holes in the table and anticipated that then-obscure components existed with properties fitting to fill those holes. He named them eka-boron, eka-aluminium and eka-silicon, with particular nuclear masses of 44, 68, and 72. The eka-prefix was utilized by different scholars, and not just in Mendeleev's own expectations. Prior to the revelation, francium was alluded to as eka-caesium, and astatine as eka-iodine. Here and there, eka-is as yet used to allude to a portion of the transuranic components, for instance, eka-actinium (or dvi-lanthanum) for unbiunium. Yet, current authority IUPAC practice is to utilize a precise component name dependent on the nuclear number of the component as the temporary name, rather than being founded on its situation in the intermittent table as these prefixes require.
Eka-silicon is germanium, though eka-aluminium is gallium. Here germanium has 4 electrons in its external most shell, henceforth it imparts electrons to chlorine, that too with 4. In the event of gallium, it has three unpaired electrons in its external most shell.

Note: Scandium oxide was disconnected in late 1879 by Lars Fredrick Nilson; Per Teodor Cleve perceived the correspondence and advised Mendeleev late in that year. Mendeleev had anticipated a nuclear mass of 44 for ekaboron in 1871, while scandium had a nuclear mass of $44.955908$ .In 1871, Mendeleev anticipated the presence of a yet-unfamiliar component he named eka-aluminium.