Final answer:
The change in internal energy for 1 mol of an ideal monatomic gas with a temperature rise of 8.0 K at constant volume is 4R.
Step-by-step explanation:
The change in the internal energy (ΔU) of an ideal monatomic gas at constant volume can be calculated using the formula ΔU = ⅓nRΔT, where n is the number of moles of the gas, R is the ideal gas constant, and ΔT is the change in temperature. Here, we have 1 mol of the gas and the temperature change is 8.0 K, so the change in internal energy ΔU = ⅓(1 mol)(8.0 K)(R) = ⅓(8.0)(R) = 4R. Thus, the change in internal energy for 1 mol of an ideal monatomic gas at constant volume with an 8.0 K temperature rise is 4R.