What coefficient is in front of oxygen in p4 + o2 -> p3o3

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.

13 protons and 14 neutrons.  this also means that the amount of electrons also is 13 because electrons have the same amount as protons..the atomic number means the amount of protons (which effectively tells you the electrons) the atomic mass, tells you the amount of protons and neutrons in the nucleus.hope this . 

Molar mass ca = 40.078 g/mol  molar mass cacl2 = 110.984 g/mol  % ca = 40.078 x 100 / 110.984 = 36.1