If you place a glass rod over a burning candle, the glass turns black. What is happening to each of the following (physical
change, chemical change, both, or neither) as the candle burns?
Explain.
a. the wax
b. the wick
c. the glass rod

(i mainly just need the whether or not it is a chemical or physical, or both, change or not.)

In a heat engine of 1000 j of heat enters the system and the piston does 500 j of work what is the final internal energy of the system if the inital energy was 2000 j we have to do all of these down here 1)write the equation 2)list out your know variables 3)plug the numbers into the equations 4)solve 5)write your solution statemtn that includes inital energuy and final energuy added