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General Chemistry

Learn the toughest concepts covered in Chemistry with step-by-step video tutorials and practice problems by world-class tutors

23. Chemistry of the Nonmetals

Alkaline Earth Metals Reactions

The reactions of the Alkaline Earth Metals are driven by the presence of two valence electrons in their outer shell. 

Reactivity of the Alkaline Earth Metals

The presence of an additional valence electron in the outer shell of the Alkaline Earth Metals make them undergo more reactions than the Alkali Metals


Reactions of the Alkaline Earth Metals

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Hey, guys, In this new video, we're gonna take a look at the reactions of the alkaline earth metals. So here, remember when we say alkaline earth metals referring to Group two Way. Remember, in group two way, we have beryllium, magnesium, calcium, strontium, barium and radium. Now here, how do they react with oxygen? We're going to say since they act as strong reducing agents, they can reduce atmospheric oxygen. So they're all in group two way, so they're plus two. Oxygen's and groups six A. So it's minus two. So the numbers are the same. So what happened? They just cancel out here to balance it out. We need to put it to here. So we'd have, for example, this could represent to M. Geo or CEO or S R. O. Now, when it comes to bury him, barium also has a special property here. Bury him, can react with oxygen gas and not form this metal oxide. This would be called a metal oxide. What would happen with barium is Baron would form B A. Oh two. Let me take myself out of the image guys. B A o. Two solid. Now here. If we calculated the oxygen oxidation number. This would actually be plus two, and this would be minus one. That way their charges cancel each other out, and that's why it's neutral. When oxygen has a charge of minus one, we refer to it as a peroxide, so this would be very in peroxide Now recall. We've also talked about peroxide when it comes to Group one A in Group one A. We saw sodium peroxide in this case would be to group on a elements with two oxygen's. So Group one A. There's two of them with two oxygen's and a group to a B one barium with two oxygen's both basically constitute peroxide. This would be sodium peroxide versus barium peroxide. When it comes to group to a barium is the only one that really does this. Now how did they react with water here? We're gonna say the heavy Group two elements. So when we talk about the heavy Group two elements, let's go back up here. So we're gonna say the heavy Group two elements are these three here calcium, strong team and barium beryllium in magnesium. They're lighter, so we don't refer to them as heavy, and then radium on the bottom is radioactive again. If it's radioactive, it's hard to predict what it's going to do, so we tend to leave it out. So coming back down here, the heavy Group two elements So calcium, strontium and barium reduce water to form elemental hydrogen. So here hydrogen was plus one. But then, over here it's natural states, with zero so going from plus one to zero. Meaning means it's been reduced here. We'd say that again. Radium is radioactive, so we don't talk about it. When it comes to beryllium and magnesium, they're not as heavy as these three, so they don't do this. Instead, they form an oxide, so they form an oxide with water. So it acts like a coating, which prevents further reaction. So we never get this far in terms of their reactions, so they would just combine with the oxygen to make oxides. Now, how do they react with Hal agents? The alkaline earth metals react with the diatonic callejon's to form Ionic Hal. It's so here they are again their in group two A. So there plus two the halogen, which you represent by X and Group one s. So there, minus one. The numbers are different. So what do we do? We crisscross them to comes here. One comes here, so we get that as an option. Now, the final thing we can look at is elemental oxides, of course, and thermal composition or decomposition. So here for elemental oxides, we're gonna stay here. All outline. Earth metals oxides are basic, with exception to beryllium oxide. Here, beryllium oxide is not basic, like all the others are. It is actually AMFA, Terek. Now, if you don't know what this word means, something that is an FA Terek can behave as both and acid or a base, and all it depends on is what it's reacting with. It could react one way with ah certain compound to act as an acid and then using a different compound, it may act as a base. So beryllium is anfo, Terek, while the other ones are basic. So here, here goes the metal oxides of them. So let's say that this was barium oxide. It reacts with water. What? What happened here to have very, um I on plus the two hydroxide ions. It's basic because it produces hydroxide ion. This is what's known as a basic ion. So again, all of them do this. Except for beryllium oxide. It is AMFA Terek. Then finally, we're going to stay here. Carbonate compounds will undergo thermal decomposition to form the oxide. Okay, so here we'd formed the metal oxide plus Co two. So, basically what I mean by this So this would represent We're talking about the carbonate compound. So let's say we had barium, which is plus two, and carbonate remembers Upali Atomic ion. The numbers are the same, so they just cancel out and you combine them together so this would decompose to give us barium oxide plus carbon dioxide gas. So this would be the example of the equation. And we'd say Here, let's say we use calcium carbonate and it underwent this thermal decomposition. This is an important reaction, because here this calcium oxide can further react to form limestone, so that's its importance in terms off environmental sciences. So as you can see the alkaline metals because of the addition of an additional balance, electron can do even mawr types of reactions than are alkaline metals. So alkaline metals or the group won medals. They have their own set of reactions aquiline earth metals takes it one step further with additional ones. Addition of Mawr Electrons opens up the door two more types of reactions.