Chemical Bond Data
The atomic radius increases with each filled shell of electrons. When the electronegativity difference between atoms is or greater, we characterize the bond. With less electronegativity, there is also less ionization energy. metal becomes more reactive because it uses less energy to fulfill its goal;. PDF | Chemical hardness () and absolute electronegativity () have important and the relationship with ionization energy (I) and electron affinity Ionization energy equations for systems that contain electron in different numbers The main goal of this project is to perform the efficacy of several ionic.
And you can have positive ions if the protons are more than the number of electrons, protons, or positive electrons or negative.
Ionization energy trends
And you can have negative ions if the number of electrons are greater than the number of protons. For example, for example, if you just had Hydrogen in it's neutral state has one proton and one electron, but if you were to take one of those electrons away then Hydrogen would have a positive charge and essentially it would just be, in its most common isotope it would just be a proton by itself.
And so, when we talk about a positive ion like this where our protons are more than our electrons, the number of protons are more than the number of electrons, we call these cations, cations.
Cation, once again, just another word positive ion. Likewise, we can have negative ions.
So, say for example, Fluorine. So, Fluorine gains an electron, it's going to have a negative charge.
It's gonna have a negative charge of negative one, and a negative ion we call an anion. And the way that I remember this is a kind of means the opposite or the negation of something. So, this is a negative ion.
We've negating, you can somehow think we are negating the ion. So, with that out of the way, let's think about how hard it will be ionize different elements in the periodic table.
In particular, how hard it is to turn them into cations. And to think about that, we'll introduce an idea called ionization energy. And this is defined, this is defined as the energy required, energy required to remove an electron, to remove an electron.
Ionization energy trends | Periodic table (video) | Khan Academy
So, it could've even been called cationization energy because you really see energy required to remove an electron and make the overall atom more positive. So, let's think about the trends.
And we already have a little bit of background on the different groups of the periodic table. So, for example, if we were to focus on, especially we could look at group one, and we've already talked about how Hydrogen's a bit of a special case in group one but if we look at everything below Hydrogen.
If we look at the Alkali, if we look at the Alkali metals here we've already talked about the fact that these are very willing to lose an electron.
Because if they lose an electron they get to the electron configuration of the noble gas before it. So, if Lithium loses an electron then it has an outer shell electron configuration of Helium. It has two outer electrons and that's kind of, we typically talk about the Octet Rule but if we're talking about characters like Lithium or Helium they're happy with two 'cause you can only put two electrons in that first shell. But all the rest of 'em, Sodium, Potassium, etc.
Lithium, if you remove an electron, it would get to Helium and it would have two electrons in its outer shell. So, you can imagine that the ionization energy right over here, the energy required to remove electrons from your Alkali Metals is very low.
So, let me just write down this is So, when I say low, I'm talking about low ionization energy. Now, what happens as we move to the right of the periodic table?
In fact, let's go all the way to the right on the periodic table. Well, if we go here to the Noble Gases, the Noble Gases we've already talked about. They're very, very, very stable. They don't want no one, they don't want their electron configurations messed with.
So, it would be very hard Neon on down has their eight electrons that mumbling Octet Rule. Helium has two which is full for the first shell, and so it's very hard to remove an electron from here, and so it has a very high ionization energy.
Low energy, easy to remove electrons. Or especially the first electron, and then here you have a high ionization energy.Electronegativity and Ionization Energy
I know you have trouble seeing that H. So, this is high, high ionization energy, and that's the general trend across the periodic table. Most atoms follow the octet rule having the valence, or outer, shell comprise of 8 electrons.
Because elements on the left side of the periodic table have less than a half-full valence shell, the energy required to gain electrons is significantly higher compared with the energy required to lose electrons.
As a result, the elements on the left side of the periodic table generally lose electrons when forming bonds. Conversely, elements on the right side of the periodic table are more energy-efficient in gaining electrons to create a complete valence shell of 8 electrons.
The nature of electronegativity is effectively described thus: From left to right across a period of elements, electronegativity increases. If the valence shell of an atom is less than half full, it requires less energy to lose an electron than to gain one. Conversely, if the valence shell is more than half full, it is easier to pull an electron into the valence shell than to donate one. This is because atomic number increases down a group, and thus there is an increased distance between the valence electrons and nucleus, or a greater atomic radius.
Important exceptions of the above rules include the noble gases, lanthanidesand actinides. The noble gases possess a complete valence shell and do not usually attract electrons.
Therefore, noble gases, lanthanides, and actinides do not have electronegativity values. This is because their metallic properties affect their ability to attract electrons as easily as the other elements.
Conceptually, ionization energy is the opposite of electronegativity. The lower this energy is, the more readily the atom becomes a cation.
Generally, elements on the right side of the periodic table have a higher ionization energy because their valence shell is nearly filled. Elements on the left side of the periodic table have low ionization energies because of their willingness to lose electrons and become cations. Thus, ionization energy increases from left to right on the periodic table. Graph showing the Ionization Energy of the Elements from Hydrogen to Argon Another factor that affects ionization energy is electron shielding.
Electron shielding describes the ability of an atom's inner electrons to shield its positively-charged nucleus from its valence electrons. When moving to the right of a period, the number of electrons increases and the strength of shielding increases. Electron shielding is also known as screening. Trends The ionization energy of the elements within a period generally increases from left to right.
This is due to valence shell stability. The ionization energy of the elements within a group generally decreases from top to bottom. This is due to electron shielding. The noble gases possess very high ionization energies because of their full valence shells as indicated in the graph.
Note that helium has the highest ionization energy of all the elements. The relationship is given by the following equation: Unlike electronegativity, electron affinity is a quantitative measurement of the energy change that occurs when an electron is added to a neutral gas atom.
This means that an added electron is further away from the atom's nucleus compared with its position in the smaller atom. With a larger distance between the negatively-charged electron and the positively-charged nucleus, the force of attraction is relatively weaker.
Therefore, electron affinity decreases. Moving from left to right across a period, atoms become smaller as the forces of attraction become stronger. This causes the electron to move closer to the nucleus, thus increasing the electron affinity from left to right across a period. Note Electron affinity increases from left to right within a period. This is caused by the decrease in atomic radius. Electron affinity decreases from top to bottom within a group. This is caused by the increase in atomic radius.
Atomic Radius Trends The atomic radius is one-half the distance between the nuclei of two atoms just like a radius is half the diameter of a circle. However, this idea is complicated by the fact that not all atoms are normally bound together in the same way.