ElectronGFactor is the electron g-factor.
FineStructureConstant is the fine structure constant, an atomic constant.
HubbleConstant is a measure of the rate at which the expansion of the universe varies with distance.
MolarGasConstant is a physico-chemical constant.
MuonGFactor is the muon g-factor.
MuonMass
(Physical Constants Package Symbol) MuonMass is the mass of a muon.
NeutronMass is the mass of a neutron.
PlanckConstantReduced is a universal constant, equal to PlanckConstant/(2 Pi).
PlanckMass is a universal constant.
ProtonMass is the mass of a proton.