How many energy levels does period 5 and period 6 have?

When molecules of water vapor in the air come in contact with a cold can of soft drink , they lose energy ,slow down,and form a liquid due to decrease in ?

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.

Calculate the number of molecules present in 0.750 mol of mgo.