Question

define a chemical reaction . state four observations which help us to determine that a chemical reaction has taken place . write one example of each observation woith balanced chemical equation​

Answer 1

a chemical reaction is the reaction in which new substance along with new properties are formed. for example rusting of iron , formation of gas ,digestion of food in our body etc. for example H2 +O2 give rise to H2o to balance it we rewritten as 2H2 +O2 give rise to 2H2o ......hope it helps you....