What fraction of the gas phase molecules initially present for 1.0 atm in the chamber are present at 1.0×10−10 torr?

The fraction of gas phase molecules is calculated by the division of final pressure to the initial pressure.

Fraction =     (1)

Here, initial pressure = 1.0 atm

final pressure =

First, convert torr into atm

1 atm = 760 torr

final pressure =

=

Now, put the value of initial and final pressure in formula (1)

Fraction =  

=  

Thus, fraction of the  gas phase molecules =

they are all solids.