Pilots of hot air balloons are able to steer them somewhat by moving them up or down to enter different air currents that move in different directions. Explain how the flame can be used to do that.

How have the greenhouse gasses increased from the year 2000 to 2018

One way that radioactive waste is treated is by burying it in repositories. the repositories are found only in states with very low populations. true or false? a. trueb. false(also i meant to put high school but it put down middle school instead)

3. how much energy in joules is required to evaporate .0005 kg of liquid ammonia to vapor at the same temperature? 4. how much energy ( in megajoules ) is given up by .75 kg of water at 0c when it freezes to form ice at 0c? 5. explain how heat works between and at critical temperatures?