why do we see water droplets on the outer surface of a glass containing ice cold water
Air has the property that at different temperature fixed amount of moisture is present in air. Ice cold water container has temperature between -4(degree)C to 0(degree)C when air comes comes in contact with ice cold container it losses it temperature. Moisture (water molecules) from air are given out which are seen in the form of water droplets.
the temperature of the ice cold water is close to zero. the air around the container consists of water vapour which accounts to humidity. when the water vapour comes in contact with the outer surface of glass containing ice cold water there is a change in physical state of water vapour to water in liquid phase due to lower temperature and condensation, hence accounting to the water droplets on the outer surface of a tumbler or glass containig ice cold water
hope it helped.