A chemical reaction occurs when reactants are converted into products. A chemical equation is a representation of a chemical reaction using chemical symbols. The chemical equation also indicates the physical state of the reactants and products. The substances that go into a chemical reaction are called the reactants, and the substances produced at the end of the reaction are known as the products.
Electronegativity is a measure of the ability of an atom to attract the electrons when the atom is part of a compound. Electronegativity values generally increase from left to right across the periodic table. The highest electronegativity value is for fluorine.