Understanding a chemical reaction.
Firstly you need to know about :-
-the symbols and elements belonging to the symbols.
-Their atomic number and number of valence electrons to balance the equation
-Know the reactants and products.The compounds on the left hand side of the arrow are the reactants and the compounds on the right hand side of the arrow are the products.
-Denote the state of matter for every compound whether it is a liquid or gas or solid.
-Gaseous products are denoted by upward arrow mark and precipitated products are denoted by down ward arrow mark.
-Some chemical reactions are accompanied by evolution of heat and are termed as exothermic reactions.
-Some reactions are followed by absorption of heat and are termed as endothermic reactions.
-If all the reactants and the products are in same phase (solid or liquid or gas) then the reaction is called as equilibrium reaction.
-In a chemical reaction extremely new substance is formed by the combination or diffusion of the products at various temperature.