Which are chemical? (Select all that apply.)
blue-black
crystalline
solid
sublimes to a violet-colored gas
reacts with aluminum and many other metals

In a heat engine if 1000 j of heat enters the system the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2000 j? 1. write the equation 2.list out your known variables 3.plug the numbers into the equations 4.solve 5.write your solution statement that includes initial energy and final