Solution

Hydrogen atom has nuclear charge of +1 and mass of 1.
Hence, the given neutral atom of an element has a nucleus with nuclear charge $$\displaystyle 11 \times 1 = 11 $$, and nuclear mass $$\displaystyle 23 \times 1 =23$$.
Now, we know that it is none other than Na atom.

The element can form a stable charged ion by losing 1 electron so that it attains stable electronic configuration of $$\displaystyle Ne $$ noble gas.

Number of electrons in neutral $$\displaystyle sodium$$ atom $$\displaystyle = $$ number of protons $$\displaystyle = 11$$
Number of electrons in $$\displaystyle Na^+$$ ion $$\displaystyle = 11-1 = 10$$.
The ratio of electrons to protons present in its stable ion will be $$\displaystyle 10:11$$.
Hence, the correct option is C .