Answer:
A. PBr5
Explanation:
To write the formulas for a compound, first identify what the elements used are.
In phosphorus pentabromide, the elements are phosphorus and bromine (bromine => bromide in a compound name). Find these symbols on your periodic table.
Phosphorus = P
Bromine = Br
Write them one after the other:
PBr
Then, determine the number of each atom, which will be written as a subscript. The word penta is the greek prefix meaning 5. Since it's attached to "bromide", there are 5 bromine atoms.
PBr₅
