Answer:
isolated system (plural isolated systems) (physics) A system that does not interact with its surroundings. Depending on context this may mean that its total energy and/or momentum stay constant.
Explanation:
An isolated system is a thermodynamic system that cannot exchange either energy or matter outside the boundaries of the system. ... The system may be enclosed such that neither energy nor mass may enter or exit.
is there both?
Answer : The final pressure of the gas will be, 26.8 kPa
Explanation :
According to the Boyle's law, the pressure of the gas is inversely proportional to the volume of the gas at constant temperature of the gas and the number of moles of gas.

or,

or,

where,
= initial pressure of the gas = 209 kPa
= final pressure of the gas = ?
= initial volume of the gas = 10.0 L
= final volume of the gas = 78.0 L
Now put all the given values in this formula, we get the final pressure of the gas.


Therefore, the final pressure of the gas will be, 26.8 kPa
Answer: The answer is the second one
Where are the following elements to choose from?