A gas is inside a cylinder fitted with a piston. The gas and its surroundings are both at \(20^{\circ} \mathrm{C}\), and the gas is compressed as the piston moves and decreases the cylinder volume. The compression takes place slowly enough to allow the gas temperature to stay at \(20^{\circ} \mathrm{C}\), and the work done on the gas by the compression is \(2.0 \times 10^{3} \mathrm{~J}\). What is the change in entropy of the gas?