Valence electrons are the electrons in the outermost shell. Those are t<span>he electrons on an atom that can be gained or lost in a chemical reaction.
</span>Elements that are left on the periodic table <span> have relatively few </span>valence electrons<span>, and can form ions more easily by losing their </span>valence electrons<span> to form positively charged cations.</span>
<span>Nonmetals are further to the right on the periodic table, so they gain electrons relatively easily and lose them with difficulty. </span>
Answer is: Yes it is balanced. It has the same number of Ca and O on both the reactant side and the product side.
According to principle of mass conservation, number of atoms must be equal on both side of chemical reaction.
There is one calcium atom atom and one oxygen atom on both side of reaction, so chemical reaction is balanced.
