For each of the following reactions (a) establish whether it is allowed or not, (b) if it is not, give the reasons (they may be more than one), (c) give the types of interaction that allow it:

(1) π^-p→π⁰+ n;

(2) π⁺→μ⁺+ ν_μ;

(3) π⁺→ μ⁺ ν̅_μ;

(4) π⁰→2_γ;

(5) π⁰→3_γ;

(6) e⁺ + e ^- → γ;

(7) p+ p̅ → Λ⁺ Λ^- ;

(8) p + p → Σ ⁺ + π⁺;

(9) n →p + e ^- ;

(10) n →p + π^-.