I need an answer now please asap and you will me marked brainiest please it's missing I need it now.
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Answer:
alll of them are possible, besides the last one
Explanation:
All of them are correct compounds besides the last one. The last one isn’t a correct compound because the second element does not exist
#NaO_2
Correct compound=Na_2O
#MgCl_2
#CaF
#NaBr
#KHe
Helium is a noble gas so can't form compounds