How many moles of hydrogen are in 50.0 l of hydrogen gas at stp? 1.39 moles 2.23 moles 0.985 moles 2.74 moles 4.56 moles?

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.

The difference between the atomic number of an element and the element’s atomic mass is the number of ions.

What are transitions between a liquid and a solid called? identify which way they are transitioning