Leiko is holding a hot mug of tea, and Ravi is holding an identical mug, but his is filled with cold water. Both of them are standing in a room that is at room temperature. What happens to the temperature of the liquid in their mugs over time?

Respond very briefly.
The temperature of the hot tea in Leiko's mug will decrease over time, while the temperature of the cold water in Ravi's mug will increase over time. This occurs because heat naturally flows from a warmer object to a cooler one until thermal equilibrium is reached. The hot tea will lose heat to the cooler surrounding air and possibly through the mug to Leiko's hands and the environment. Conversely, the cold water in Ravi's mug will gain heat from the warmer surrounding air, also through the mug's material from the environment or from Ravi's hands, until the water's temperature is the same as that of the room.