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प्रश्न
Compare and contrast the arrangement of elements in Mendeleev’s periodic Table and the Modern Periodic Table.
उत्तर
| Mendeleev’s periodic table | Modern periodic table |
| Elements are arranged in the increasing order of their atomic masses. | Elements are arranged in the increasing order of their atomic numbers. |
| There are 8 Groups. | There are 18 Groups. |
| Each groups are subdivided into sub group ‘a’ and ‘b’ |
Groups are not subdivided into sub-groups.
|
|
Groups for Noble gas was not present as noble gases were not discovered by that time.
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A seprate group is meant for noble gases.
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There was no place for isotopes.
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This problem has been rectified as slots are determined according to atomic number.
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APPEARS IN
संबंधित प्रश्न
Explain why, the first period of the periodic table has only two elements whereas second period has eight elements
What are the advantages of the periodic table?
State the main aim of classifying elements. Which is the more fundamental property of elements that is used in the development of Modern Periodic Table? Name and state the law based on this fundamental property. On which side of the periodic table one can find metals, non-metals and metalloids?
State the modern periodic law for classification of elements. How many (i) groups and (ii) periods are there in the modern periodic table?
An element E has following electronic configuration:
|
K |
L |
M |
|
2 |
8 |
6 |
(a) To which group of the periodic table does element E belong?
(b) To which period of the periodic table does element E belong?
(c) State the number of valence electrons present in element E.
(d) State the valency of the element E.
What is meant in the periodic table by a period?
In the Modern Periodic Table – atoms of all elements are arranged according to their increasing order of – atomic numbers. An atom of nitrogen has seven protons and seven electrons. State what would be its atomic number.
Give the symbol and valency of the following element and radical.
Zinc
“Hydrogen occupies a unique position in Modern Periodic Table”. Justify the statement.
An element with atomic number ______ will form a basic oxide.
