Question

what is the valency of N in N2O AND NO2

Answer 1

Valency is the combining capacity of an element.
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Nitrous oxide is also known as laughing gas with chemical formula N2O
Valency of N in N2O:
As it is a molecule total valency=0
Let X be N valency
Oxygen valency is - 2
2*X - 2=0
2X=2
X=1
Hence valency of N in N2O=1
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Valency of N in NO2:
Let X be the valency of N
X +2(-2)=0
X=4
So, valency of N in N2O = 4
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Answer 2

Valency of Oxygen is always -2.
So in these compounds valency of Nitrogen can be calculated by following ways.
1.
In N2O:
Let X is the valency of Nitrogen N So
2*X+(-2)=0
2X=2
X=1
In N2O valency of Nitrogen is +1.
2.
In NO2:
As oxygen valency is always -2.
Let X is the valency of Nitrogen N So
X+2*(-2)=0
X-4=0
X=4
In NO2 valency of Nitrogen is +4.