This happens because the temperature at which oxygen changes from a gas to a liquid is about 13 degrees Celsius above that of nitrogen. The oxygen can be seen dripping from the can just as on a humid day you can see drops of water condense and drip from a can you take from the refrigerator.
Though you technically can join the military up to age 42, if you're 35 or over you'll need an age waiver if you've never been in the military before.
The Military Separation Guide for Active Duty Personnel: Itâs never too early to begin preparations for your separation from active military service. The Department of Defense (DoD) recommends that you start your planning at least 12 months prior to separation, and 24 months prior to retirement, from active duty.