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प्रश्न
Match the columns.
| Column A | Column B |
| 1) Eka-aluminium | a) Scandium |
| 2) Eka-Silicon | b) Gallium |
| 3) Eka-boron | c) Germanium |
| d) Beryllium |
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उत्तर
| Column A | Column B |
| 1) Eka-aluminium | b) Gallium |
| 2) Eka-Silicon | c) Germanium |
| 3) Eka- boron | a) Scandium |
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संबंधित प्रश्न
Besides gallium, which other elements have since been discovered that were left by Mendeleev in his Periodic Table? (any two)
What were the criteria used by Mendeleev in creating his Periodic Table?
Which of the following statements is not a correct statement about the trends when going from left to right across the periods of periodic Table.
What property do all elements in the same column of the Periodic Table as boron have in common?
What property do all elements in the same column of the Periodic Table as fluorine have in common?
An atom has electronic configurations 2, 8, 7.
What is the atomic number of this element?
Name two elements whose properties were predicted on the basis fo their positions in Mendeleev's periodic table.
Which group of elements could be placed in Mendeleev's periodic table later on, without disturbing the order? Give reason.
State the periodic law on which Mendeleev's periodic table table was based. Why and how was this periodic law changed?
State the merits of Mendeleev's classification of elements.
Describe two anomalies of Mendeleev's periodic classification of elements.
What name were given by Mendeleev to the then undiscovered element scandium.
What name were given by Mendeleev to the then undiscovered element gallium?
What name were given by Mendeleev to the then undiscovered element germanium?
How do the properties of eka-aluminium element predicted by Mendeleev compare with the actual properties of gallium element?
Why did Mendeleev leave some gaps in his periodic table?
In Mendeleev's periodic table, why was there no mention of noble gases like helium, neon and argon?
State any three limitations of Mnedeleev's classification of elements.
Besides gallium, which two other elements have since been discovered for which Mendeleev had left gaps in his periodic table?
Which group of elements was missing from Mendeleev's original periodic table?
According to Mendeleev's periodic law, the elements were arranged in the periodic table in the order of: ______
In Mendeleev's periodic table, gaps were left for the elements to be discovered later on. An element which found a vacant place in the periodic table later on is:
(a) Be
(b) Si
(c) Ge
(d) Se
Mendeleev predicted the existence of certain elements not known at that time and named two of them as eka-aluminium, and eka-silicon.
(a) Name the element which has taken the place of (i) eka-aluminium, and (ii) eka-silicon
(b) Mention the period/periods of these elements in the modern periodic table.
(c) Write the group/ groups of these elements in the modern periodic table.
(d) Classify these elements as metals, non-metals or metalloids.
(e) How many valence electrons are present in the atoms of each of these elements?
State the merits of Mendeleev's classification of elements.
The elements from the zero group are called ______.
Find the correlation:
Eka boron : Scandium : : Eka Aluminum : ______
Find the odd one out and give its explanation.
Find the odd one out and give its explanation.
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 |
Write the name.
The family of elements having zero valency.
Write a scientific reason.
In a group, the size of the atom increases as it goes down from the top.
Describe the merits of Mendeleev’s periodic table?
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?
Match the column:
| Column ‘A’ | Column ‘B’ |
| Alkali metals | (a) Group 18 |
| Halogens | (b) Group 1 |
| Noble gases | (c) Group 17 |
