Formula: $E=mc^2$.

$$
E=mc^2
$$

Parameter $1, $2.

```math align=center
E=mc^2
```

See: $\ce{Fe^3+}$

```math align=center
\ce{Hg^2+ ->[I-] HgI2 ->[I-] [Hg^{II}I4]^2-}
```