Question

pls suggest an easy way to memorise all the valencies of elements

Answer 1

Just remember their electronic configuration.
By learning this, You can sort out all questions related to an atom

Answer 2

Just remember the electronic configuration of each element which is very simple..

If the last shell electron is 1,2,3,4 ; Then the valency us the same as the last shell electron...

If the last shell electron is 5,6,7,8
Just subtract the valence electrons by 8
As 8 forms the octet rule

So if it is 5 ; Valence = 3
If it is 6 ; Valence = 2
If it is 7 ; Valence = 1
If it is 8 ; it is a rare gas/Noble gas it's valence is 0

Hope this helps!!
cheers!! :)

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