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Sizes of Particles & their Properties Flashcards

All 6 cards in this deck

What size range of structures does nanoscience refer to?

11–100100 nm, of the order of a few hundred atoms.

What range of diameters do fine particles (PM2.5) have?

Between 100100 nm and 25002500 nm, i.e. 1×10−71\times10^{-7} m to 2.5×10−62.5\times10^{-6} m.

What range of diameters do coarse particles (PM10) have, and what are they often called?

Between 1×10−51\times10^{-5} m and 2.5×10−62.5\times10^{-6} m; they are often referred to as dust.

What are the steps to express a particle size given in nanometres as a size in metres in standard form?

e.g. a particle of diameter 4040 nm

  1. Recall 11 nm =1×10−9= 1\times10^{-9} m
  2. Multiply: 40×10−940\times10^{-9} m
  3. Write in standard form: 4×10−84\times10^{-8} m

How do the dimensions of nanoparticles compare with the typical size of atoms and molecules?

Nanoparticles (11–100100 nm) are only a few hundred atoms in size; a single atom is about 0.10.1 nm across.

What are the steps to calculate the surface area to volume ratio of a cube?

e.g. a cube of side 22 cm

  1. Surface area =6×= 6 \times side2=6×2×2=24 cm2^2 = 6\times2\times2 = 24\ \mathrm{cm^2}
  2. Volume == side3=2×2×2=8 cm3^3 = 2\times2\times2 = 8\ \mathrm{cm^3}
  3. Ratio =24:8=3:1= 24 : 8 = 3 : 1