JAMB - Chemistry (2004 - No. 2)
A chemical reaction is always associated with
an increase in the composition of one of the substance
a change in the volume of the reactants
a change in the nature of the reactants
the formation of new substance
Paliwanag
Chemical reactions always involve the formation of new substances. This is because chemical reactions change the arrangement of atoms in a substance, which creates new substances with different chemical properties.