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प्रश्न
Elements in the same group show the same valency. Give scientific reason.
उत्तर
(a) The number of valence electrons in the outermost shell of an atom of an element is equal to the valency of an element.
(b) The number of valence electrons for all the elements in a group is the same. Therefore, the elements in the same group have the same valency.
(c) For example, the elements of Group I such as sodium (Na) and potassium (K) contain only one valence electron, and so, the valency of elements of Group I is one. Similarly, for Group II, the valency is two.
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संबंधित प्रश्न
The elements 4Be, 12Mg and 20Ca, each having two valence electrons in their valence shells, are in periods 2, 3 and 4 respectively of the modern periodic table. Answer the following questions associated with these elements, giving reason in each case:
(a) In which group should they be?
(b) Which one of them is least reactive?
(c) Which one of them has the largest atomic size?
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Why do elements in the same group show similar properties but the elements in different groups show different properties?
How does the atomic size vary on going down from top to bottom in a group of the periodic table? Why does it vary this way?
How does the tendency to lose electrons change as we go down in group 1 of the periodic table? Why does it change this way?
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Given alongside is a part of the periodic table. As we move vertically downward from Li to fr?
| Li | Be |
| Na | |
| K | |
| Rb | |
| Cs | |
| Fr | |
| rA | Ra |
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(a) A, B, C
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(d) B, D, E
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Explain
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| Li | Be | B | C | O | F | Ne |
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| Li | Be | B | C | O | F | Ne |
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Name and state the following with reference to the elements of the first three periods of the periodic table.
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Answer the following question:
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Name or state following with reference to the element of the first three periods of the periodic table.
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Select the correct answer from the options given below.
It is a metal in period 2 having electronic configuration 2, 1?
