[en] Experimental data analysis are studied for the decays of elementary particles. The decays of μ, tau, π, eta, n, K, Λ, Σ, Ψ and Ω particles are considered. It is shown that taking into account the intrinsic characteristics of hadrons, leptons, photons and spurions, the decays happen according to the simple selection rules: ΔI₃=0, ΔSsub(PI)=0 (ΔB=0, ΔL=0, ΔQ=0). Here Ssub(PI) is the total strangeness, Ssub(PI)=S+R. Moreoveri in the case of strangeness nonconservation each strange particle emits a corresponding definite spurion