Which element does X represent in the following expression: 2512X? Enter the chemical symbol of the element. 4. A 1.6 kg block of iron at 23 C is rapidly heated by a torch such that 15 kJ is transferred to it. What temperature would the block of iron reach (assuming the complete transfer of heat and no loss to the surroundings)? If that same amount of heat (15 kJ) was quickly transferred to a 810 g pellet of copper at 33 C, what temperature would the copper reach before it begins losing heat to the surroundings? Use the equation for heat capacity and the following heat capacity values: qcs, Fe(s)cs, Cu(s)===mcsATO.450 J/(g. C)0.385 J/(g-C)