In terms of valence electrons, explain why metals form positive ions.

Explanation:

Metal elements form positively charged ions called cations because they are located on the left side of the periodic table These elements all have valence electrons in an s orbital. These electrons are relatively easy for the atom to lose to achieve a stable octet of electrons in its outermost energy shell.

the potential energy of the reactants is 200j.

from the energy diagram, the energy of the product formed is 350j; this means that, this reaction is an endothermic reaction, because it absorbs energy from its environment.

it's c. elements are placed in rows based on how may valencies electrons have.