Bihar Police Constable Model Paper 5

EXPLANATION:

• Valence electrons are the electrons that occupy the outermost orbitals of an atom.
• These electrons have a weak attraction towards the atomic nucleus; thus, atoms can easily remove or share these electrons with other atoms.
• The atomic number of Chlorine is 17.
• The electronic configuration of chlorine is 2, 8, 7 $\left(1{\mathit{s}}^{2}2{\mathit{s}}^{2}2{\mathit{p}}^{6}3{\mathit{s}}^{2}3{\mathit{p}}^5\right)$ and is distributed in the shells K, L, M respectively.
• From the above electronic configuration of chlorine, it is clear that, in last orbit of Cl, there are 7 electrons. Therefore option 1 is correct.