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प्रश्न
Which group of elements was missing from Mendeleev's original periodic table?
उत्तर
Group 18 consisting of noble gases was missing from Mendeleev's original periodic table as the noble gases were not known at that time.
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संबंधित प्रश्न
Name two elements whose properties were predicted on the basis fo their positions in Mendeleev's periodic table.
Besides gallium, which two other elements have since been discovered for which Mendeleev had left gaps in his periodic table?
In Mendeleev's periodic table, gap was not left for one of the following elements. This element is:
(a) gallium
(b) beryllium
(c) germanium
(d) scandium
Why could no fixed position be given to hydrogen in Mendeleev's periodic table?
State the merits of Mendeleev's classification of elements.
The elements from the zero group are called _______.
Eka boron : Scandium : : Eka Aluminum : _______
Match the columns.
| Column A | Column B |
| 1) Eka-aluminium | a) Scandium |
| 2) Eka-Silicon | b) Gallium |
| 3) Eka- boron | c) Germanium |
| d) Beryllium |
An atom has electronic configurations 2, 8, 7.
To which of the following elements would it be chemically similar? (Atomic numbers are given in parentheses.)
Which one of the following does not increase while moving down the group of the periodic table?
