What happens to the average speed of the particles

Cis the answer ur welcome if i get it wrong u don't have to me

Answer is:     molar solubility of  yttrium fluorid is 4.23·10⁻⁶ m. balanced chemical reaction: yf₃(s)  → y³⁺(aq) + 3f⁻(aq). ksp = 8.62·10⁻²¹. ksp = [y³⁺]  · [f⁻]³.[y³⁺] = [yf₃] = s.[f⁻] = 3[yf₃] = 3s.ksp(yf₃)  = s  · (3s)³.8.62·10⁻²¹ = 27s⁴.s(yf₃)  =  ⁴√(8.62·10⁻²¹  ÷ 27).s(yf₃)  = 0.00000423 m.s(yf₃) = 4.23·10⁻⁶ m.

Firstly, the planetary model of the atom  failed  to explain why individual atoms produce discrete  line spectra. in fact, according to rutherford's model, each individual atom should produce a  continuous  line spectrum. the second flaw to his model was the fact that electrons orbit the nucleus in a circular fashion.