Answer:
C. It is reactive because it must gain two electrons to have a full outermost energy level.
Step-by-step explanation:
The electron configuration of this element ends in 2s²2p⁴.
A filled energy level would end in 2s²2p⁶.
The element will be reactive, because it must gain electrons to have a full energy level, and it needs two more electrons to do this.
.sand and water
.iron fillings in a liquid
.cereal in milk
