To calculate the change in temperature of a 21 kg aluminum block that absorbs 1.5 x 10^5 J of energy, the formula Q = m x c x ΔT is used, where Q is the heat absorbed, m is the mass, c is the specific heat capacity of aluminum, and ΔT is the change in temperature. The specific heat capacity of aluminum must be referenced to complete the calculation. The discussion also notes the correct spelling of aluminum, emphasizing the "-ium" suffix common in metal names. Understanding these concepts is essential for solving the problem accurately. The conversation highlights both the calculation method and a linguistic point about metal nomenclature.