How many liters of hydrogen gas are needed to react with cs2 to produce 6.5 l of ch4 at stp

Connect the whole numbers on the periodic table to indicate what they represent?

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

State one important difference between a physical change and a chemical change?