It shows an error when I type "\ch{NH3}." How do I write the chemical formulae? Although it is cumbersome when dealing with complex reactions, I know I can use the "\text" commmand as "\text{NH}_3".
A graduated cylinder is meant to be read with the surface of the liquid at eye level, where the center of the meniscus shows the measurement line. Is it also true for any non-transparent or a colored liquid? There're some diverse information in different sources.
Illustration source
The Periodic Table
The Periodic Table