How are elements arranged on the periodic table? a. they are arranged to highlight similarities between elements
b. they are arranged to highlight different elements with similar isotopes
c. they are arranged in order from most abundant to very rare and unstable
d. they are arranged in order of the date of discovery

The answer is b because a,c,and d are opinons

The answer is not c

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⁻

Iron reacts with oxygen in a chemical hand-warmer. how should this reaction be categorized? the correct answer is: a). as an exothermic process because it releases heat