# Ea is the term for activation energy, what is the mean of a in this term?

Our doctor said it is not stand for activation. it stands for something else, any help will be appreciated.

• Comments are not for extended discussion; this conversation has been moved to chat. – jonsca Jan 28 '19 at 22:59

The subscript $$\mathrm a$$ in $$E_\mathrm a$$ may refer to Arrhenius.
An empirical parameter characterizing the exponential temperature dependence of the rate coefficient, $$k$$, $$E_\mathrm a = RT^2 \frac{\mathrm d(\ln k)}{\mathrm dt}$$, where $$R$$ is the gas constant and $$T$$ the thermodynamic temperature.