Which of the following substances cannot be used for lenses?

(A) Water

(B) Soil

(C) Plastic

(D) glass

For light of wavelength 589 nm, calculate the critical angles for the following substances when surrounded by water.

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For light of wavelength 589 nm, calculate the critical angles for the following substances when surrounded by water.

   glycerine   °

fused quartz   °

  flint glass   °

For light of wavelength 589 nm, calculate the critical angles for the following substances when surrounded by air.