Chemical Formulae Flashcards

All 3 cards in this deck

Give the formulae of the molecules of hydrogen, oxygen, nitrogen and chlorine as they exist as elements.

$H_2$, $O_2$, $N_2$, $Cl_2$ — these elements are diatomic.

When are brackets used in a chemical formula?

e.g. a compound of $Ca^{2+}$ and $OH^-$

When more than one of an ion containing several atoms is needed: $Ca(OH)_2$

True or false? Writing chlorine as CL instead of Cl is still acceptable in a formula.

False. Only the first letter of a symbol is a capital, so it must be $Cl$ (and $Cl_2$ for the molecule).