Atoms that have the same number of outer electrons OA.
are all metallic elements.
B. must be atoms of the same element.
OC.
are all nonmetallic elements.
OD.
belong to the same family of elements.

I can see two answers, I’d go with D, but all neutral atoms, of the same element would have the same number of outer electrons. However, if you consider that some of the atoms might be ions, that would eliminate B.

Abbreviated as mg-25.

Combustion is the act or process of burning. therefore, i believe the answer is  a: burning wood.