Equal amounts of gases A and B are placed in a closed reactor. A and B react to combine into AB in the following equilibrium reaction: A + B ⇌ AB

Which are true about this system?

Select two that apply.

A closed system allows for the transfer of energy in and out, so energy is not conserved in this system
The total mass in the reactor remains the same because products are removed from closed systems.
The total mass in the reactor gradually becomes zero because mass is consumed in closed systems.
The total mass in the reactor remains the same because mass is conserved in closed systems.
A closed system does not allow for the transfer of energy in and out, so energy is conserved in the system.
The total mass in the reactor gradually becomes zero because products are removed from closed systems.