Solve the following problem and round the correct number of significant figures?
4.5 x 2.34 = ?

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.

Which metal exist in liquid state and can be cut with knife ?

How many moles of al3+ ions are in 1.25 moles of al2o3