I have exams coming up for science. can yall help me with study ideas?
(I'm in 7th grade)
I WILL VOTE YOU BRAINLIEST IF YOU ANSWER FIRST!!!

Which of the following is a compound? a.carbon b.oxygen c.hydrogen d.water

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

How do cfcs cause ozone depletion? how do cfcs cause ozone depletion? ultraviolet radiation breaks down cfcs, molecules containing chlorine. chlorine then breaks one oxygen atom away from ozone, leaving behind a paired oxygen molecule. ultraviolet radiation breaks down cfcs, molecules containing chlorine. chlorine then breaks two oxygen atoms away from ozone, leaving behind a paired oxygen molecule. ultraviolet radiation creates cfcs, molecules containing chlorine. chlorine then breaks two oxygen atoms away from ozone, leaving behind a paired oxygen molecule. ultraviolet radiation creates cfcs, molecules containing chlorine. chlorine then breaks one oxygen atom away from ozone, leaving behind a paired oxygen molecule.