Hello I have a very important question. I really do understand why it takes energy to remove a electron from a atom. Because the electron is negatively charged and drawn toward the nucleus which is positive. Electron affinity is very confusing because it says that adding a electron to a atom releases energy. But electrons, especially the outer electrons are high energy so I seem to think that adding an electron adds energy to the atom instead of releasing. Thank you very much for helping
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Hey Alvino!
So.. The best way I can describe this is to compare it to electronegativity of an atom or element. Electronegativity is the tendency of an element or molecule to attract shared electrons(between two elements or molecules). Take HCl for example.. On the periodic table electronegativity increases from left to right (across periods) So Cl is a lot more electronegative than H right? So the electrons will be drawn more to the Cl as opposed to the H.
Electron affinity is the change in energy between two molecules that results from adding an electron to one of those molecules. So in order to gain that (negatively charged) electron, some energy is required/released in order to change the energy between two molecules( and for the other element to accept those electrons since the electrons themselves are already negatively charged). Think of it like this... If you are carrying a bag and you are adding things to it.. What's happening? The bag is getting heavier and you are exerting more and more energy to hold that bag. Lets say at first it was empty, then you added 5lbs, then 10lbs, then 20lbs. The change in energy you used is going to be a lot higher from when the bag was empty to when the bag had 20lbs in it. So the energy you are "adding to the bag" to hold it up, that energy is actually getting released since you are exerting it. It is the same exact things for elements, as those electrons are being drawn to that other element (its electronegativity is what determines this) their electron affinity gets higher and energy is being released due to the process of drawing in those electrons.
Does that clear anything up? I tried to give you the very basic breakdown of it. If you need further clarification or even a more detailed explanation please let me know and I can try and give you more. Also don't forget about our online Zoom Chemistry tutoring session next Monday @ 7pm! I will be hosting it ! Good luck !