<span>In exothermic reactions, the products have less enthalpy than the reactants, and as a result, an exothermic reaction is said to have a negative enthalpy of reaction. This means that the energy required to break the bonds in the reactants is less than the energy released when new bonds form in the products.</span>
At the left side if it is nonmetal then upper right
A substance undergoing thermal expansion will expand when heated, substances will mostly expand when heated but when their cold it will undergo contraction.
Dwarfs - A
Giants - C
Main Sequence Stars - B
Supergiants - D