26.Measurements of the radiation from an astronomical source showed a decrease in the wavelength at which the greatest energy was being received. This could mean that the source had

27.The molar heat capacity of an ideal gas at constant pressure is greater than that at constant volume because

28.A temperature may be measured by using a constant volume gas thermometer and measuring the pressure of the gas both at the triple point of water and at the unknown temperature. Which one of the following procedures is necessary if two gas thermometers, using different real gases, are to agree ?

29.One mole of an ideal gas requires 207 J heat to raise the temperature by 10 K when heated at constant pressure. If the same gas is heated at constant volume to raise the temperature by the same 10 K, then the heat required is