Question

How do we calculate valency of an atom

Answer 1

Explanation:

if if the number of electrons in the last shell are from 1 to 4 then the valency of the electrons are from 1to 4 only

when the last cell contains 5 or more then the valency will be 8 - the number

For example: oxygen

electrons in last shell =6

therefore valency is 8-6=2

Answer 2

hlo mate here is ur ans...

1)Before moving towards the find out valency of the elements you should must know the atomic no. of the elements it will make you easier to find out the valency.

2)Shells K,L, M,N.

3)K denotes the first shell (or energy level), L the second shell, M, the third shell, and so on.

4)Number of electrons to fill the shells in K shell we can fill the 2 electrons, L= 8 electrons , M= 8 electrons so on...

5)If the number of the electrons in outer shell 1,2,3, 4 then it will be consider as it is.

6)Example of Boron at. No. is 5 and electronic configuration is 2 , 3, so as per shell in k shell there will be 2 electrons fill and the remaining 3 will shift into the L shell so 3 will be the valency of boron.

7)And if the outer most shell have the more than 5 electrons at that time you have to prefer this formula. ( Valency = 8 - ve- ) where ve- valence electrons.

8)Example chlorine at. no. is 17 electronic configuration is 2 , 8, 7, so outer shell have 7 electron we will find out the valency by using formula.

9)Valency = 8 - ve- = 8 - 7 = 1 so valency of the chlorine is 1

10)In case of noble gases valency will be zero because of completely filled shells.

Example Argon at. no. is 18 and electronic configuration is 2 , 8 , 8,

Valency = 8 - ve- = 8 - 8 = 0

hope it helps to you

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