7. Which of the following is a statement of the first law of thermodynamics? \text { A) } \mathrm{E} \mathbf{k}=\frac{1}{2} \mathbf{m v}^{2} B) A negative AH corresponds to an exothermic

process. \text { C) } \Delta \mathbf{E}=\text { Efinal - Einitial } D) Energy lost by the system must be gained by the surroundings. E) 1 cal = 4.184 J (exactly)