General Chemistry

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23. Chemistry of the Nonmetals

The Alkali Metals named for the basic solutions that they create represent the Group 1A Elements

Reactivity of Alkali Metals

A majority of the reactions experienced by the Group 1A elements are the result of having only 1 valence electron in their outer shell.  


Reactions of the Alkali Metals

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Hey, guys, In this new video, we're gonna take a look at the alkaline metals of the periodic table. So here we were talking about the alkaline metals of the periodic table. We're talking about group one A. So remember when we're talking about these medals in group wanted, we have hydrogen which will not consider as part of this group because hydrogen is not a metal, it's a nonmetal. So we're gonna say here below hydrogen, we have lithium, sodium, potassium. We have our B, C s and f are. So we're talking about about these here These elements here below hydrogen in Group one A. Now we're gonna say here their name for the basic solutions that they tend to form. Okay, So alkali, alkaline, Right. So we have alkaline solution versus acidic solutions. Alkaline solutions are basic solutions now, because of their low Mueller masses, larger atomic radi I and N s one electron configuration. They tend to be very malleable and they tend to have low densities, melting points and boiling points. So let's go back and talk about some of these principles so they have lower Mueller masses. Because if we take a look at the periods, the rose, the periodic table. Right. If you look, they all begin the period of each row right there, the first element in each row. And as we move from left to right of the rose, the masses are increasing. So the group went elements represent the lowest Moeller masses for each row. Now also, we're gonna say, Remember the periodic trend If you haven't seen those videos yet, I recommend that you do use them in conjunction with this video here to get a better understanding what's going on here? Remember, when it comes to atomic radi I atomic radio, I decrease as we go from left to right of the periodic table but it increases as we go down. Right? So if Group One aids over here on this side, they tend to have larger atomic radio compared to the other elements of the periodic table and here for electron configuration, all of them are in the S block the first row of the S block. That's why there s one now. That means that they all have one valence electron in their outer shell now larger size and one electron out in the balance electron shell means that there is a very low attraction for that electron to the nucleus. So it's gonna be very easy for us to rip off that electron now, because it's very easy for us to rip off that electron. Or it's gonna have low ionization energy so we can put along with this. It has low ionization energy. And remember, ionization energy is the energy to remove an electron because it's so easy to remove that one Valence electron. We're gonna say that these metals are tend to be found not in a neutral state, but in there, plus one cat ion state. Now I've said multiple times when it comes to the periodic table, the natural forms off metals is in their solid form, right, so sodium solid. But that's not exactly true. They actually have to be prepared in a lab or in a plant to get this form here. This solid sodium form, naturally sodium, doesn't exist like this in our environment, instead exist as n a plus. It has to be treated so that I could get this neutral form, and here we say, very malleable. That means I can shape them. I can mold them and in fact, potassium, for example. It's super valuable. I can take a lump of potassium and put it in my hand and squeeze it and change it into different shapes, almost like silly putty sodium. Not so much the moisture from your hand could cause a violent reaction to occur. Now we're gonna say here, how did they react with water? Now, almost all the alkali metals are water soluble, so you throw them into water, they're going to dissolve, and in fact they create highly exo, thermic heat of hydrogenation. So what does this mean? That means that they give off a ton of heat when I dumped them in tow water. And in fact, as you go down the group, it becomes more and more violent. So if I take a lump of sodium and I throw it in tow water, there's gonna be an explosion because the reaction is so exo, thermic and as they go down, the group and I take pieces of group won a medal. The explosions get bigger and bigger, more and more violent, so there's a very high explosive eggs ultimate process off water. Reacting with these group won eight medals. Now here. We're gonna say in this process, hydrogen is reduced because if we take a look, we're gonna say hydrogen here is with oxygen. When hydrogen is with a non metal, it's oxidation numbers plus one. And then here it's H to its natural state. So it's oxidation. Number is zero. So it's going from h goes from being plus one 20 So you're gonna say it's oxidation number decreased, and because it's oxidation number decreased, it was reduced again. If you don't remember what these terms mean, go back and take a look at our rearm equations and videos dealing with redox reactions, oxidation and reduction reactions. Now, how did they respond to reacting with oxygen? So we're gonna need to write a few things out here, So let me take myself out of the image. Alright. So first of all, we're gonna say the alkaline metals react with elemental oxygen to form different types of oxides. So here in group one A are metals are lithium sodium. We have potassium here R B C s and F R. Now we're gonna say here lithium, the way we lithium reacts with oxygen, we're gonna say lithium here would be plus one. Oxygen is a group six sites would be minus two, so the numbers are different. So the two from here would come here and the one from here would come here. So that would give us ally to Oh, this would be lithium oxide. Now, after that, it gets a little bit different. Next up is sodium. Now, sodium doesn't behave the same way. In fact, what happens with sodium is sodium becomes and a And for those of you have seen my videos on Redox reactions. Remember, if you have a group one element, two of them connected to two Oxygen's, this represents a peroxide. So again, a peroxide is to group elements with two oxygen's, so this would be sodium peroxide. And then we're gonna say that potassium R B and C s all behave the same way. So we group them is just M. What they do is they just combined with Theo to outright and they become a super oxide. A super oxide is ah, group one element with two oxygen's. So here we have que 02 r B 02 CSO to all of these will be super oxides. This one here, Frank. See, um, is radioactive. So the way it reacts with oxygen is hard to predict, so we tend not to talk about it. But we talk about the other group winning medals above it. Now here these group winning medals can also react with Callejon's diatonic Callejon's, which just means two of them together to form Ionic Hal. It's remember your halogen czar flooring, chlorine, bromine and iodine in Group Seven? A. We don't talk about asked a team because that is also radioactive. The way it behaves is unpredictable, so we tend to leave it out as well. Now here we'd say that their group won a medal, so they're all plus one. The Halogen Zahren group. Seven days so there, minus one. So when they combined to give us M X and here the represent a solid here. Since we have two, Group one is and two how logins we put it to here so it be balanced. So the group went elements. There are quite a bit of them. They have specialized properties because of the position on the periodic table. Here is the thing that you need to recall when it comes to how they act with water with oxygen and with Callejon's