An electron transitions from n = 5 to n = 3 in a hydrogen atom. What is the energy required for this transition? Is energy emitted or absorbed in the transition?

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

The enthalpy of formation of water is -285.8 kj/mol. what can be inferred from this statement?

Harvey kept a balloon with a volume of 348 milliliters at 25.0˚c inside a freezer for a night.  when he took it out, its new volume was 322 milliliters, but its pressure was the same.  if the final temperature of the balloon is the same as the freezer’s, what is the temperature of the freezer? the temperature of the freezer is  kelvins.