How is a polar covalent bond different from a non polar covalent bond?

What is the molar mass of a gas that has density of 2.054 g/l

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

#20 which type of bond is formed when bases pair in dna? ionic bond covalent bond coordinate bond hydrogen bond