Why does water in an open container slowly decrease due to evaporation?

Correct answer: Water becomes vapour and goes into the air

Direct answer: A, because some liquid water changes into vapour and enters the air. At the exposed surface of an open container, water molecules are moving continuously. Some surface molecules gain enough energy to escape from the liquid into the surrounding air. This gradual surface change is evaporation, so the amount of liquid left in the container decreases. The water has not disappeared; it has changed state and mixed with the air as water vapour. B is wrong because evaporation does not turn water into stone. C is wrong because water does not become soil through this process. D is wrong because a colour change would not explain the loss of liquid volume. A closed container may also have evaporation, but vapour can remain inside and condensation may balance it; an open container allows vapour to disperse more easily. Memory cue: open surface plus liquid changing to vapour equals evaporation.