Charles' Law states that a gas expands and increases in volume when heated, but the relationship between volume increase and temperature rise depends on the system. It is a specific case of the ideal gas law, represented by the equation pV=nRT, which assumes constant internal energy and applies to isothermal processes. In isobaric processes, where pressure remains constant, an increase in volume indicates that the gas is doing work on its surroundings. For an ideal gas, potential energy between particles is negligible, leading to the equation U= (3/2)nRT for monoatomic gases. Consequently, the change in internal energy (ΔU) is related to temperature change (ΔT) and work done (w). If no heat is exchanged with the surroundings, the temperature will decrease. In cases where external pressure is zero, the gas can expand without doing work, resulting in constant temperature.
