To draw atoms, follow the steps below.
You can represent atoms in a molecule with practically any arbitrary symbol instead of standard atomic symbols by creating aliases. An alias can be defined and edited by using the Atom Label Editor. Alternatively, they can be created on the Advanced tab of the Periodic Table dialog.
Marvin is chemically intelligent, that is, implicit hydrogens are added and charges are set according to valence rules. To metalloid elements, hydrogens are added by default.