* All separate questions that I needs answers to* Thank you
What element has 12 electrons when the atom is electrically neutral?
What element is in the alkaline-earth metals group and has 20 protons?
This element has 7 electrons when the atom is electrically neutral?

Idon’t know what the answer is i wish i could

Heating it up with cause a quicker reaction time

Pretty sure it's d. heterogeneous is separated by physical properties. 

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⁻