Answer:
2475042
Explanation:
P = Pressure = [/tex]1\times 10^{-8}\ N/m^2[/tex]
V = Volume = 1 cm³
T = Temperature = 19.5 °C
R = Gas constant = 8.341 J/mol K
[tex]N_A[/tex] = Avogadro's number = [tex]6.022\times 10^{23}[/tex]
n = Amount of substance
From ideal gas law we have
[tex]PV=nRT\\\Rightarrow n=\frac{PV}{RT}\\\Rightarrow n=\frac{1\times 10^{-8}\times 1\times 10^{-6}}{8.314(273.15+19.5)}\\\Rightarrow n=4.11\times 10^{-18}[/tex]
Number of atoms is given by
[tex]n\times N_A\\ =4.11\times 10^{-18}\times 6.022\times 10^{23}\\ =2475042\ atoms[/tex]
The number of atoms in this vacuum is 2475042
