Answer and I will give you brainiliest

Please help

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 ?

Which of the following is an example of units for speed

True or false when elements combine to form a mixture, the resulting chemical properties may be very different from those of the elements that make it.