Which phrase is an example of what electrostatic forces hold together?

a. fr atoms and localized in iron

b. he atoms in helium gas

c. oxygen and hydrogen atoms in oh-

d. na+ and br- in nabr

i'm not sure about this one.

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

Which statement best describes the he properties of iconic compounds ?

Is the flow of energy during vaporizing more like the flow during melting or during freezing