Answer:
The electrons are lost from the valence shell (outermost electron shell) of the atom.
Explanation:
This is able to be inferred not only because valence electrons being lost first is a trend but also because the atom in question has actually 3 valence electrons (13-2-8 = 3).
In a chemical reaction, the difference between the potential energy of the products and the potential energy of the reactants is equal to the heat of the reaction<span>. This is, the net energy released or absorbed (change) during a chemical reaction is the sum of the potential energy of the products less the sum of the potential energy of the reactants.</span>
