Charge number having stripped off all electrons, the charge number is identical with the atomic number "Z", which corresponds to the number of protons in ordinary atomic nuclei. Unlike in chemistry, subatomic particles with electric charges of two elementary charges (e.g. some delta baryons) are indicated with a superscript "++" or "−−". In chemistry, the same charge numbers are usually indicated as superscript "+2" or "−2". In particle physics, the charge number is a (derived) flavor quantum number. For color-charged particles like quarks and hypothetical leptoquarks, the charge number is a multiple of 1/3. Charge number Charge number ("z") refers to a
Mass-to-charge ratio a scalar property, meaning that it can be either positive (+) or negative (−). The Coulomb (C) is the SI unit of charge; however, other units can be used, such as expressing charge in terms of the elementary charge (e). The SI unit of the physical quantity "m"/"Q" is kilogram per coulomb. The units and notation above are used when dealing with the physics of mass spectrometry; however, the "m"/"z" notation is used for the independent variable in a mass spectrum. This notation eases data interpretation since it is numerically more related to the unified atomic mass unit. The "m"