The relative atomic mass of an element is: A. the mass of its atoms co pared to the mass of a carbon-12 atom.

B. The mass of its atoms averaged over time.

C. The mass of its isotopes compared to the mass of a normal atom.

D. The mass of only the neutrons in the atoms nucleas.​

Ions gain or lose electrons

Ithink the correct answer is 3

Electron equations of the given changes are as follow,a)                              cu      →      cu⁺²  + 2e⁻b)                              mg⁺²  +  2 e⁻      →      mgc)                              cl⁻    →      cl  +  1e⁻d)                              s  +  2 e⁻    →      s²⁻e)                                o²⁻      →      o  +  2 e⁻f)                              p  +  3 e⁻    →      p³⁻g)                              fe²⁺    →      fe³⁺  + 1 e⁻h)                              s²⁻    →      s⁴⁺  +  6 e⁻

Ithink ur answer would be c hope u have a good day: )