until is spent
Depending on concentration of agent and filter type, it can be anywhere between about several hours to 24 hours.
it depends on how much u travel
a cloud is not alive. if u mean how long does it stay in existence well uve come to the right place. they evaporate and condensate anytime a Chinese boy touches his pet dolphin.
I guess when heated molecules escape their liquid form
Roughly about one hundred years, give or take ten (according to most scientists).