The volume of a cylindrical chamber is controlled by a movable piston. A sample of gas is placed in the chamber, and the volume is allowed to change from \(0.0100 \mathrm{~m}^{3}\) to \(0.100 \mathrm{~m}^{3}\) at a constant temperature. If the entropy of the system increases by \(6.91 \times 10^{18}\) during the volume change, how many gas particles are there in the chamber? \({ }^{\circ}\)