
80-1
Water and water vapor can be found everywhere. Because of the asymmetrical distribution of their elec-
tric charge, water molecules are easily adsorbed on almost any surface, where they are present as a mono-
or mu
ltimolecular
la
yer
of mo
lecules
. Wa
ter
va
por
in th
e
ai
r
or an
y
ot
her
ga
s
is ge
nerally
ca
lled
hu
midity;
in liquids and solids, it is usually designated as moisture. e determination of humidity and moisture,
as in prediction of oods, fog, conditions for the appearance of plant diseases, etc., is of great economic
importance. Stored foodstus or raw materials may dry up at low humidity or get moldy at high humid-
ity. In many ind ...