Is the dehydration process a physical or chemical change? why?

Which of the following statements is true about planck’s law

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?

The diagram below shows the different phase transitions that occur in matter. which arrow represents the transition in which dew is formed?