Ans:
This is we know: λ = 1 / [(N/V) π
r2]
where r is the radius of a molecule.
numerical estimates
Molecular cross-sectional area: π r2 ≈
10-19 m2
Mean free path (sea level): &lambda ≈ 10000 m ≈ hundreds of molecular diameters
So,
Molecular density (sea level): N/V = P/kT ≈ 1 x 1015 molecules/m3
Cross section: 3) Mean & Free. Calculate the mean free path in Earth's atmosphere. Use sea...
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