What is valency? If atomic number of an element is 4, what would be the valency of the element?
Answers
Valency:-
The ability of an element to gain or loss electrons to attain the nearest noble gas configuration is called it's valency. It can also be defined as the number of valenced electrons in the outer most shell.
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It is given that atomic number of an element is 4 and we have to find its valency. To find its valency first we have to find its electronic configuration.
We know that first shell ( k) has capacity to hold 2 electrons and 2nd shell (L) has capacity to hold 8 electrons. So only 2 electrons will fit into first shell and rest have to be arranged in the 2nd shell. 2nd shell has capacity to hold 8 electrons. After completion of duplet by first shell, 2 electrons will remain in the 2nd shell.
So it's electronic configuration will be:-
2,2
In order to attain noble gas configuration, this element has to loss 2 electrons or gain 6 electrons to complete it's octet. It will loss 2 electrons because it is easy for it to loss 2 electrons rather than gaining 6 electrons also it will be the nearest noble gas configuration. So it will loss 2 electrons to gain noble gas configuration. We know that number of electrons gained or shared to attain noble gas configuration is called valency.
Since it losses 2 electrons, it's valency will be 2.
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Learn more!!
If atomic number of an element is 8 what will be it's valency?
Electronic configuration of element will be:-
2,6
Since to obtain noble gas configuration, it can either loss 6 electrons or gain 2 electrons. It will be easy to gain 2 electrons rather than lossing 6 electrons. So it will gain 2 electrons. We know that the number of electrons gained or loss is called it's valency.
It will gain 2 electrons, so it's valency is 2.