If the change of enthalpy of this reaction when proceeding left to right is +14 kcal, which chemical equation is correct?

n2o4 2 no2 + 14 kcal

n2o4 + 14 kcal 2 no2

Nebulae are enormous clouds in outer space. they are made mostly of hydrogen gas, helium gas, and dust. some nebulae glow brightly, while others do not. the stars that people see are huge, bright balls of glowing gas. they are made mostly of hydrogen and helium. which statement correctly describes other ways in which nebulae and stars are different? a. stars can form inside a nebula but a nebula can never be produced by any star. b. a star always has a higher density than a nebula. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star.

Why do electrons further from the nucleus have more energy

Which of the following is true for a reliable scientific source? it cites logic. it cites opinions. it cites valid data. it cites common sense.