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Structure of the Atom — Science STD 9 — Question

Gujarat BoardEnglish MediumSTD 9ScienceStructure of the Atom3 Marks
Question
An atom $X$ has $4$ protons and $5$ neutrons with electronic configuration $2, 2.$ Give information about its.
  1. Atomic number.
  2. Mass number.
  3. Valency.
✓

Answer

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 $= 2$
  1. Since, protons =electrons = atomic no.
So atomic no. is $4$
  1. Mass Number = No. of Protons + No. of Neutrons
$= 4 + 5 = 9$
  1. Now electronic distribution, $K = 2, L = 2$
So as the outermost shell has $2$ electrons, so the valency will be $2$

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