Answer -C They are defined by the number of electrons.
An orbital is a function that describes the probability of finding the electron with certain energy at certain distance from the nucleus therefore, it is defined by the number of electrons.
Answer:
~Na+1 is already in the preferred form. Because of this, the second ionization energy of sodium is higher than normal. Mg+1 loses an electron to form s2 p6 .
I didn't see any statements, but here are some similarities of those elements:
They all have the same number of valence electrons, they will become cations, they all will lose 2 electrons, they will behave similarly in chemical reactions, they have similar chemical properties, they all are in the alkaline earth metal family. Hope this helps! :)
