A chamber with a fixed volume of 1.0 m3 contains a monatomic gas at 3.00 102

Question:

A chamber with a fixed volume of 1.0 m3 contains a monatomic gas at 3.00 × 102 K. The chamber is heated to a temperature of 41.00 × 102 K. This operation requires 10.0 J of heat. (Assume all the energy is transferred to the gas.) How many gas molecules are in the chamber?