Hey! If someone could help me out I would really appreciate it even if it was just one answer. I'm really stuck on 3. Its second year of chem!

Which compound contains both ionic and covalent bonds? a) hbr b)cbr4 c)nabr d) naoh

Describe the forces both attractive and repulsive that occur as two atoms move closer together.

Nitric acid can be formed in two steps from the atmospheric gases nitrogen and oxygen, plus hydrogen prepared by reforming natural gas. in the first step, nitrogen and hydrogen react to form ammonia: (g) (g) (g) in the second step, ammonia and oxygen react to form nitric acid and water: (g) (g) (g) (g) calculate the net change in enthalpy for the formation of one mole of nitric acid from nitrogen, hydrogen and oxygen from these reactions. round your answer to the nearest .