electron affinity Flashcards
What is first electron affinity?
Is the energy released when one mole of electrons is added to one mole of an gasesous atom.
Is the first electron affinity usually exothermic?
Yes
Why are the 2nd and 3rd electron affinities endothermic?
They are endothermic(enrgy being absorbed),as one mole of electrons is being added to one mole of a negative ion.
Why are 2nd and 3rd electron affinities endothermic?
They are endothermic because energy is required to overcome forces which are repulsive.This is between negative ion and electrons,which are incoming.
What factors affects electron affinity?
Atomic radius,shielding and the nuclear charge.
How does the atomic radius affect the electron affinity?
The greater the atomic radius the weaker the attraction between electrons and the nucleus,so less energy is released.
What would the electron affinity be like if the atomic radius is less?
The attraction between electrons and nucleus would be more.Therfore,more energy is released.
How does nuclear charge affect the electron affinity?
The higher the nuclear charge the greater the attraction bewteen the incoming electron and the nucleus.Therfore,the higher the electron affinity as more energy is released when an electron is added.
How does shielding affect the electron affinity?
The greater the shielding,the weaker the attraction between the incoming electron and the nucleus.The electron affinity is less.
What is the trend for elements as you go across a period?
There is an increase in electron affinity as you go across a period.So elements become more exothermic
What is the trend for elements as you go down the group?
As you go down the group the electron affinity decreases,becomes less exothermic.
