Question #03ed1

1 Answer
Jul 11, 2016

Atomic number of Sodium, #"Na"# is #11#. Orbital filling of its eleven electrons is shown below
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#1s^2 2s^2 2p^6 3s^1#

In other words its electronic arrangement is #2,8,1#. Meaning it has single electron in the valence shell.

The completely filled shells corresponding to principal quantum number #n=1 and 2# are very stable.

We have observed that elements, while forming chemical bonds, follow the octet thumb rule. Atoms of main-group tend to combine in such a way that each atom has eight electrons in its valence shell, the same electronic configuration of a noble gas.

Sodium atom can either gain #7# electrons or lose#1# to attain this stable configuration. It is easier for a sodium atom to lose its extra electron and become a sodium cation having charge #+1# in the process
#" "Na -> Na^+ + e^- #