It can be an element or a compound
Explanation:
Atoms are at their most stable when their outermost energy level is either empty of electrons or filled with electrons. Sodium atoms have 11 electrons. Two of these are in the lowest energy level, eight are in the second energy level and then one electron is in the third energy level.
Hey Madoudou
The correct answer is option B (sulfate)
The reason is because "Sulfate" has a negative sign.
In order for it to be a cation, it must have positive sign such as "iron(lll)ion
I hope this helps~