Question

An atom has 4 protons and 5 neutrons what is its valency

Answer 1

Protons = 4
Neutrons = 5

Number of protons = Number of electrons
Number of electrons = 4

Electronic Configuration
= 2,2

Number of Valence electrons in the outermost shell = 2

Valency = 2
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Answer 2

since, protons =electrons =atomic no.
so atomic no.is 4
now electronic distribution =K=2 ,L=2
so as the outermost shell has 2 electrons so the valency will be 2 .......