Ncert Exercises & Solutions

Which of the following is a correct statement?

1.	The presence of reacting species in a covered beaker is an example of an open system.
2.	There is an exchange of energy as well as matter between the system and the surroundings in a closed system.
3.	The presence of reactants in a closed vessel made up of copper is an example of a closed system.
4.	The presence of reactants in a thermos flask or any other closed insulated vessel is an example of a closed system.