feat: export charge_number and mass_energy function

src/ChargedParticles.jl

@@ -16,7 +16,7 @@ include("./display.jl")
 include("./_special_particles.jl")
 
 export AbstractParticle, Particle, ChargedParticleImpl
-export mass, charge, atomic_number, mass_number, element
+export mass, charge, charge_number, atomic_number, mass_number, element, mass_energy
 export is_ion, is_chemical_element, is_default_isotope
 export electron, proton
 end

src/properties.jl

@@ -28,6 +28,8 @@ function mass(p::AbstractParticle)
     end
 end
 
+charge_number(p::AbstractParticle) = p.charge_number
+
 """Return the electric charge of the particle in elementary charge units"""
 charge(p::AbstractParticle) = p.charge_number * Unitful.q