Which of the following processes requires maximum energyMg(g) ⟶ Mg+(g)+e–Mg+(g) ⟶Mg+2(g)+e–Na(g)⟶ Na+(g)+e–Na+(g)⟶Na2+(g)+e–

The process that requires maximum energy is the one that involves removing an electron from an already positively charged ion. This is because the positively charged ion will strongly attract the negatively charged electron, requiring more energy to remove it.

In the given options, the processes are:

1. Mg(g) ⟶ Mg+(g) + e–
2. Mg+(g) ⟶ Mg+2(g) + e–
3. Na(g) ⟶ Na+(g) + e–
4. Na+(g) ⟶ Na2+(g) + e–

The second and fourth processes involve removing an electron from a positively charged ion (Mg+ and Na+ respectively).

Comparing these two, Mg has a higher atomic number than Na, meaning it has more protons in its nucleus and thus a stronger positive charge. Therefore, it will attract the electron more strongly.

So, the process that requires maximum energy is: Mg+(g) ⟶ Mg+2(g) + e–.