The students could tell whether the reaction is exothermic by measure the increase in temperature of the mixed substances using a thermometer.
Those reactions which produces heat in the form of energy is known as exothermic reaction.
So to tell whether the reaction is exothermic in nature student should measure the temperature of the reaction beaker befor adding the reactants and after the mixing of reactants.
Hence student could measure the increase in temperature of the mixed substances using a thermometer.
To know more about exothermic reaction, visit the below link:
https://brainly.com/question/972207
#SPJ2