Question

How can we see our breath ,
when the climate is cold ?

Answer 1

When youexhale(breatheout), your breath also containsmoisture. Because your mouth and lungs are moist, each breath youexhalecontains a little bit of water in the form of watervapor(the gas form of water). For water to stay a gas in the form of watervapor, it needs enough energy to keep its molecules moving. Inside your lungs where it's nice and warm, this isn't a problem. When youexhaleand it's cold outside, though, the watervaporin your breath loses its energy quickly. Rather thancontinuingto move freely, the molecules begin to pack themselves closely together. As they do so, they slow down and begin to change into either liquid or solid forms of water. Thisscientificprocess is calledcondensation. When youexhalewhen it's cold outside, the watervaporin your breath condenses into lots of tiny droplets of liquid water and ice (solid water) that you can see in the air as acloud, similar tofog. When it's warm out, though, theinvisiblewatervaporgas staysinvisible, because the warm air provides energy that allows the watervaporto remain a gas. As temperatures drop, it's more likely that you'll be able to see your breath. There's no exacttemperatureat whichcondensationwill occur. Manyenvironmentalfactors other thantemperaturecan play a role incondensation, includingrelativehumidity(the amount ofmoisturein the air). When it falls below 45° F (7.22° C), though, you can usually expect to be able to see your breath.