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प्रश्न
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 |
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उत्तर
| Column A | Column B |
| 1) Triads | b) Dobereiner |
| 2) Octave | e) Newland |
| 3) Atomic number | d) Moseley |
| 4) Atomic mass number | a) Mendeleev |
APPEARS IN
संबंधित प्रश्न
The element eka-silicon in Mendeleev’s periodic table is known as ………… in the modern periodic table.
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?
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?
In the classification of the them known elements, Mendeleev was guided by two factors. What are those two factors?
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 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?
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?
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?
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 : _______
Two elements in the same position : demerit of Newland's octaves : : place for Isotopes : _______
Match the columns.
| Column A | Column B |
| 1) Eka-aluminium | a) Scandium |
| 2) Eka-Silicon | b) Gallium |
| 3) Eka- boron | c) Germanium |
| d) Beryllium |
Write the name.
The family of elements having zero valency.
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 |
