Ionization energy of Mg+?

Question

A: It will be equal to the ionization energy of Li.

B: It will be equal to and opposite in sign to the electron affinity of Mg.

C: It will be equal to and opposite in sign to the electron affinity of Mg+.

D: It will be equal to an opposite in sign to the electron affinity of Mg+2.

Answer 1

Should be D...

Periodic trend of Ionization energy is the same as electronegativity. Increases going Top Right. Compared to Lithium we can't tell which one takes preference, but since we're considering Mg+, it already had it's first electron removed. In this problem we are looking at second ionization energy. Second electron is always much harder to remove than the first one, so second IE (ionization energy) is always much greater than first IE. A is false.

Electron affinity is the energy required to add an electron to an atom. Ionization is the energy required to take away an electron from an atom. So they are equal and opposite in sign, but we have to look at the equations of electron addition and removal.

Mg+-->Mg(2+) + e- (Removal, Ionization Energy)
Mg(2+) + e- -->Mg+ (Addition, Electron Affinity)

The equations are just reversed, so by Hess's Law Ionization energy of Mg+ is equal to and opposite in sign from Electron affinity of Mg(2+)

Answer 2

A false (higher)

B) yes

C) false

D)false