[????]?? ?? ??

?? (Vacuum)?? ?
? ???? `Vacua`?? ??
? ??? ??? ?? ????? ?? ?? ??? ??
? ??? (1 ??) ??? Gas? ??? ??? ??
- ? 2.5 ? 1019molecular/cm3??? ?? ??? ??? ??

??? ???? (1/3)
? ?? : ?? ??? ??? 1g ? ???
(????? ?? = 1.66 x 10-24 g => ?? 1 g = 6.02 x 1023 ?)
? gas? ?????? ??
: ?? ?? ??? ??? ??? ????? ???? ??
: gas? ?????? ????? ???? ??? ??

? ???? 20¡æ Ar gas = 3.94 x 104 cm/sec
? ?? : ?? ?? ? ?? ?. (= nmv2/3)
? ?? : P = P1 + P2
? ????
1 ?? = 760 mmHg = 760 torr = 1013 mbar = 1.0 x 106 Pa = 14.7 psi
1 Pa = 1 N/m2 = 7.5 x 10-3 torr

??? ?? ?? (2/3)
? ????? ?(N0) : 0¡æ, 1 atm, 22.4 liter => 6.023 x 1023
? Number density of gases : STP => 2.7 x 1019 #/cm3
1 mtorr, l um3 => 35?

? Monolayer : ?? cm? 1?? ???? ??? ?, ??(A g/cm3),
??? (B g/mole), ????? ? (N0 #/mole)
=> ???? = (?? x ????? ?) / ??? = A N0 / B (#/cm3)
=> 1 cm ? ?? = (A N0 /B)1/3, ? ?? = (B/A N0)1/3
=> monolayer = (A N0 / B)2/3

ex) Ti ?? = 4.51g/cm3, ??? = 47.9g/mole
monolayer ?? = 1.476x1015 ?, monolayer ?? = 2.6?