The molar solubility of calcium fluoride, caf2, is 2.0 x 10^-4m. what is the concentration of fluoride ion in a saturated solution?

Answer is: concentration of the fluoride ion is 0.0368 M.
Chemical reaction: CaF₂(s) → Ca²⁺(aq) + 2F⁻(aq).
Ksp = 2.0·10⁻⁴ M.
Ksp = [Ca²⁺] · [F⁻]².
[Ca²⁺] = x.
[F⁻] = 2[Ca²⁺] = 2x.
Ksp = x · (2x)².
2.0·10⁻⁴ = 4x³.
x = [F⁻] = ∛(2.0·10⁻⁴ ÷ 4).
[F⁻] = 0.0368 M.

Explanation:

Thermoseeting is termed to the plastic which caanot be remouled by heating, hence reausing them is not possible effeciently hence must be avoided to use in day to day  applciations.

bakelite is an an examle

The reverse of the "thermosettin" are "thermoplastic" which can be remolded and are good for long time use.