I am writing a proof where I have to mention both with density and of a material and mass concentration (mass/volume) of a material.

I am using the letter $\rho$ to represent density, and I didn't want to abuse the same symbol for concentration because it will make the whole proof much harder to follow. I would also prefer to avoid subscripts as the only distinguishable element.

What other symbol or syntax should I use to distinguish density from mass concentration of a material?

  • $\begingroup$ Will $c\mathstrut$ do? $\endgroup$ Jul 12, 2019 at 11:08
  • $\begingroup$ @IvanNeretin If that's a accepeted convention, yes... but I actually have other constants named c :P $\endgroup$
    – cinico
    Jul 12, 2019 at 11:15

1 Answer 1


According to IUPAC's Green Book [1], both $γ$ and $ρ$ can be employed to denote mass concentration. Fragment of a table from the section 2.10 GENERAL CHEMISTRY [1, p. 48]:

$$ \begin{array}{llll} \hline \text{Name} & \text{Symbol} & \text{Definition} & \text{SI unit} \\ \hline \ldots \\ \text{mass concentration, (mass density)} & γ, ρ & γ_\ce{B} = m_\ce{B}/V & \pu{kg m-3} \\ \ldots \\ \hline \end{array} $$

[…] In polymer science the word “concentration” and the symbol $c$ is normally used for mass concentration.

Also, from the SI Brochure, [2, p. 139]:

$$ \begin{array}{lll} \hline \text{Derived quantity} & \text{Typical symbol} & \text{Derived unit expressed} \\ & \text{of quantity} & \text{in terms of base units} \\ \hline \ldots \\ \text{mass concentration} & γ, ρ & \pu{kg m-3} \\ \ldots \\ \hline \end{array} $$


  1. IUPAC “Green Book” Quantities, Units, and Symbols in Physical Chemistry, 3rd ed.; Cohen, R. E., Mills, I., Eds.; IUPAC Recommendations; RSC Pub: Cambridge, UK, 2007. ISBN 978-0-85404-433-7.
  2. BIPM. Le Système International d’unitès / The International System of Units (“The SI Brochure”), 9th ed.; Bureau international des poids et mesures: Sèvres, 2019.
  • 1
    $\begingroup$ Thanks. I never saw it before, but in IUPAC I'll trust and I shall use $\gamma$. $\endgroup$
    – cinico
    Jul 12, 2019 at 14:39

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.