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प्रश्न
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
उत्तर
(b) Beryllium.
In Mendeleev's periodic table, a gap was left for gallium, scandium and germanium.
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संबंधित प्रश्न
How could the Modern Periodic Table remove various anomalies of Mendeleev’s Periodic Table?
What property do all elements in the same column of the Periodic Table as fluorine have in common?
Name two elements whose properties were predicted on the basis fo their positions in Mendeleev's periodic table.
State the merits of Mendeleev's classification of elements.
The correct formula of the oxide of Eka-aluminium element predicted by Mendeleev was:
(a) EaO3
(b) Ea3O2
(c) Ea2O3
(d) EaO
The elements from the zero group are called _______.
Two elements in the same position : demerit of Newland's octaves : : place for Isotopes : _______
Match the columns.
| Column A | Column B |
| 1) Triads | a) Mendeleev |
| 2) Octave | b) Dobereiner |
| 3) Atomic number | c) Thomson |
| 4) Atomic mass number | d) Moseley |
| e) Newland |
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.)
Match the column:
| Column ‘A’ | Column ‘B’ |
| Alkali metals | (a) Group 18 |
| Halogens | (b) Group 1 |
| Noble gases | (c) Group 17 |
