[firefiremx]

I would like to ask the following question

1) What is the number concentration of aerosol at the mass concentration of 50µg/m^3 if the particles are
(a) 0.1µm, and (b) 10µm in diameter?
Assume standard density (1g/cm^3)

2) Calculate the volume ratio and mass ratio in ppm of these particles

3) What are the surface areas per cubic meter of this amount of particles at these two diameters?

THANK YOU VERY MUCH

[Borek]

Please read forum rules.

You have to show your attempts at solving the question to receive help. This is a forum policy.

[firefiremx]

(a) Volume of one particle = 4/3 pi (0.05)^3
                                     = 1/6000 pi µm
     Mass of one particle = (1/6000 pi) /10000 = 1.67 x 10^-8 g
     Number of particles in 50µg = 50 / 0.0167 = 3000
    5000 per m^3

Am I right for part a? THANK YOU!

[Borek]

Your approach in general looks OK, but the result is off - pay attention to unit conversion.

[firefiremx]

Your approach in general looks OK, but the result is off - pay attention to unit conversion.

THX
I will check the unit conversion