Nucleon number

Proposed Entry

The nucleon number is the number of nucleons in a molecule. It is a unitless physical property with symbol N.

N = n

Comments

There used to be another name for the same property: the Mass number. This name, however, is misleading because a unitless quantity should not be called "mass". The symbol for the quantity nucleon number used to be m, which is even more unfortunate because m is the official symbol of a mass quantity.

The nominal mass M has a simillar meaning as the nuclear number, but it is not dimensionless. It is a mass measured in the Atomic Mass Unit, also called Dalton.

M = z Da

where z is an integer value.

References

see Mass