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प्रश्न
Why was this basis of classification discarded for future classification of elements?
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उत्तर
Basis of rejection:
- Some characteristics being considered, varied under different conditions.
- Certain elements resembled metallic as well as non-metallic both.
- It did not serve the purpose of classification.
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संबंधित प्रश्न
The element which can from an acidic oxide should be the one whose atomic number is:
(a) 6
(b) 16
(c) 12
(d) 19
An element X from group 2 reacts with element Y from group 16 of the periodic table.
(a) What is the formula of the compound formed?
(b) What is the nature of bond in the compound formed?
A metal X is in the first group of the periodic table. What will be the formula of its oxide?
The following diagram shows a part of the periodic table containing first three periods in which five elements have been represented by the letters a, b, c, d and e (which are not their chemical symbols):
-
1 18 a 2 13 14 15 16 17 b c d e
(i) Select the letter which represents an alkali metal.
(ii) Select the letter which represents a nobles gas.
(iii) Select the letter which represents a halogen.
(iv) What type of bond is formed between a and e?
(v) What type of bond is formed between d and e?
The elements Li, Na and K, each having one valence electron, are in period 2, 3 and 4 respectively of modern periodic table.
(i) In which group of the periodic table should they be ?
(ii) Which one of them is least reactive ?
(iii) Which one of them has the largest atomic radius ? Give reason in justify your answer in each case.
(a) How is possible valency of an element determined from the electronic configuration of its atom ?
(b) Determine the valency of an element X whose atomic number is 15.
If the distance between two Cl atoms in a Cl2 molecule is 1.98Å, then the radius of the Cl atom is ______.
Which one of the following does not increase while moving down the group of the periodic table?
Element ‘A’ has electronic configuration 2, 7; ‘B’ has electronic configuration 2, 8, 5 and ‘C’ has electronic configuration 2, 8, 7. Which two elements will exhibit similar chemical properties?
How are elements grouped into various families in the periodic table?
