All right, there we are. So first one correct. Correct. Yep, two Marks. All right, how many Marks for this one? Oh, six, so six Marks. So to get six Marks, you need to describe at least three adaptations and an explanation of at least two of them. So a lot of this area. Which maximizes the amount of sunlight that's good. Okay, spongy mia fell. Good stomata. Brilliant. Okay. So I don't even need to mark the last part. You have done enough to get the full six Marks there. Good. Well done, Linda. Question two. Right, testing a leaf of starch. Sunlight. Boiling water. Okay. I'm going to return these to the chat. So you've got a record of these. First one. And next one. So no Marks lost so far. Let's go to the next one. Done done. And then I think it was your homework. It's a bit big. Explain how the presence of start shows that photosynthesis has occurred to Marks, glucose is produced and glucose is stored as Stuto Marks. Plant a. Okay, so plant a did not photosynthesize. Which is why no glucose and the iodine didn't change. Yeah photosynthesis occurred, glucose change to starch brilliant or Marks x. Question three right now, where 3.1 gone. Let's put this on and then I'll find 3.1. I think I've put them in the wrong order. Yeah, that's the first one. Root hair cell. Oh, excuse me, still sneezing. Is that because like this sickness like last week, well, it's just been like a month now, Linda, I actually felt like I got a bit better. And now it seems like it could be coming back again. It's just or maybe I've caught something else, I don't know, but it's Yeah the never ending sickness started before Christmas. Crazy. Right 3.2. Right. Just one mark, you just need to say increases the surface area, right? So you weren't sure about this one. Have you done osmosis before? No. Okay. So let me give you, let me give you the pen and then you can write in the answer for this. So you need to say water moves. From an area of high water concentration. Brackets in the soil. To an area of low water concentration. Brackets in the roots. No, don't write brackets, right? So the point here is if you just put high concentration to low concentration, you wouldn't get the mark, because that would just be like diffusion. So you must remember, osmosis is a special kind of diffusion where it is water molecules that are moving. So you must say high water concentration to low water concentration. All right? That's that one. Xylem transports water and minerals stick. Now you didn't cover osmosis at school, so I'm not too worried. You will definitely be covering it when you do gcse se. Schools do cover things at slightly different times, so I'm not concerned that you haven't done it. Oh, I've lost another one, haven't I? Let's go and find that. There we go. So this is the next one. Magnesium deficiency is shown by yellow leaves. Three Marks, magnesium is needed to make chlorophyll one mark. So you lost a mark there because you didn't say and can you write this on you didn't say chlorophyll. Is a Green pigment. Brackets found in chloroplasts. Which absorbs sunlight. Or photosynthesis. Can you just change that to red so that just stands out a bit? Okay. So that's where you lost one mark on that one. And you could have had nitrates or phosphates or potassium for this answer. You've chosen nitrates. And they are used to convert glucose to proteins. Put those on the chat. And that was the end. Good. So starting off our new topic now, now we're either going to do one lesson or we'll do two lessons together depending how quickly we get through it. Now this is a chemistry topic. So of course, there will be quite a lot of the practiticals that we can't actually do. So we will be able to move faster. And quite possibly you will have done those at school anyway. So chemical reactions. Is what we're going to start with. And can you read that, please, Linda? Learning objective to understand the characteristic of chemical reactions success criteria, to define what is met by a chemical reaction, to investigate the signs of a chemical reaction, to compare chemical reactions to physical changes. Eight quite straight ightforward just an introduction. Don't expect therebe anything tricky there for you. So let's get into it. Give you some examples of where substances change. Like melting, like winyeah. Give me a couple more. Like when you like burn something, it like turn like to ash. Yeah, good. When like you could Collan egg. Mm, Yep, brilliant. Now obviously some of those are physical and some of those are chemical. And we will come on to that and you will, I'm sure I've done that primary level anyway. Salt dissolving, fuel burning. Yeah you said that one. Yeah. Making a cake with your eggs in there, boiling water and fizzing chemicals so we can see something happening in all of those instances. However, sometimes these changes are chemical and sometimes are physical. So which are which? You want to maybe circle the physical or circle the chemical up to you egchaocircle of the physical ones. They're like physical, right? And now I'm going to ask you to explain why and what is a physical change. Like there's they're like you didn't make it happen, like it happened naturally. And like it like doesn't like change substance. Like it doesn't like this is it doesn't like make like a new substance. Yeah, that's important point. Okay. So it's not about whether you made it happen or not because you still made the salt dissolving water. So it's whether a new substance is made or not. And then what's the other thing that you can do with physical but not with chemical? It changed like shape. It's about whether they are reversible or irreversible. Yeah, it can be reversed. Okay? So you can get the original substances back again. Now just because the water has disappeared into the air, that's not the point because we could do something, we could put a lid on it and we could trap the water and it would condensate back to liquid again. Okay, so we've got a definition of that. So do not make new substances and are usually easily reversible. Change of states such as boiling water is a physical change. Water changes from liquid to gas. The chemical composition of the water does not change. It is still exactly the same substance. So if you cool the steam, it will change back to liquid again if you don't let it escape into the room. Alright, chemical however you read this one, chemical changes occur as a result of chemical reaction. When a chemical reaction takes place, the existing chemical bonds between the atoms are broken, the atoms are rearranged, and new chemical bonds are made. Chemical reactions make new substances as atoms has been rearranged. Chemical reactions are usually irreversible. Okay. And I'm presuming that you're happy with what an atom is. And what a chemical bond is. Okay. With that, Linda, from a previous topic. Yeah. Okay, good. So chemical reactions involve the making and breaking of bonds, and completely new substances are made so they are irreversible. Often when you are looking at bonding and chemistry, you will have little Popper beads. And then the little sticks here represent the bonds. So the balls are the atoms, and those are the bonds. So what are we going to need to happen to make these bonds break? Like add another substance. We're going to need some kind of energy to make the bonds break as well, aren't we? Because presumably, if the bonds are intact, then the substance must be quite stable. So we've got to do something to give it a push to break those bonds. Just like in photosynthesis, you need some light energy to make those bonds start to break. So the bonds have been broken, the atoms have been rearranged, and new comical bonds are made, and we've made a new substance. And the new substances are chemically different to the starting substances. Chemical reactions. Right now, just think let me just check this note. That's fine. So chemical reactions take place everywhere. We've seen that they take place in plants. There's lots of them taking place in the human body, such as in your stomach as part of digestion, reactants and products. We're happy with that. Reactant becomes product. Came reactants the things that are reacting together. Products are things that are made. So I know you're happy with that. So how do we know? I think I'm going to do my first yei'm I going to do my first sheet. Just a little simple overview. I'm going to put that together. Right. Okay, Linda, can you cut those out and then put them in the correct place? I'm just gonna try and line this up. This does not want to line up. Come on. Yeah. About as good as we can. I can. So you've got a strange thing on your iron one. I don't you can like pick it off, okay. Have we done the iron one? Alright, so all of them, Oh, you've got it as well. Okay. So now put them into physical or chemical. Don't worry about getting them to fit. That's fine. Yeah, don't worry too much. I'm not going to save this. So don't worry if it doesn't all line up. Okay, good. Quite straightforward. Tell me about the glass breaking. It's like I watched like the elemental thing, and I ththat like everyy's heat. You can like put it back. Absolutely. Now, it would be very difficult to stick all of those to glue the pieces back and younever have it quite perfect, would you? So you could, of course, melt it, and then you could reform your glass, your conical flask. So Yeah. Right. The next part of the lesson is a practical, which of course, we can't do. So we're just go through each of the. Experiments, let's talk about them quickly, and then we can move on. So how do we know if a chemical reaction has taken place? What sorts of things do we want to look for? Like anent color, Yeah. Like. Like when there's like gas produced, Yeah fizing over blanket. When like it changes state. Be careful because that could just be a change of state. Like. There's like a new substance. Yeah, okay, flames. Now think about temperature. What might happen to the temperature of the substance? It's like. I'm going to become like there's going to be like heat. Now, does it always increase in temperature? No, sometimes the opposite might happen. It will decrease in temperature. And that's two different types of reactions. Have you talked about endoothermic and exothermic reactions? They probably Yeah probably going to be in this topic. I think you'll be coming on to them shortly. Okay. So changes in temperature. Right, so burning magnesium ribbon. So have you done this one at school? So Yeah, we use like those things to like look to reduce you like the greenish fire. Yeah. Was it blue glass? It was like this wood and like there's like this blackish thing in the middle and you like look through it. Yeah you have to be very careful because magnesium burns very, very brightly and it can damage the retina at the back of your eye. So that's often why this is done as a teacher demonstration. So basically, you hold the magnesium in the bunsome flame. It burns very, very brightly. But what are you left with at the end? Like this black thing, it should have been the White powder. Yeah should have been a White maybe I like just didn't remember. Yeah, that's fine. Okay. So you obviously get a change. It looks completely different. Citric acid and sodium hydrogen carbonate. So what do you think you're going to get with these ones? The temperatures going to change, right? What else? Bubbles. So you're going to see fizzing. Now this one, you will actually see the temperature go down. So this is one of those reactions which is called endothermic. So the temperature decreases. Lead nitrate and potassium iodide. So these are both clear solutions. So the lead nitrate is clear, the potassium iodide is clear. When you put them together, you get a color change and you get a yellow precipitate. Magnesium and hydrochloric acid. Okay, we have got a thermometer again, so that is a clue. What do you think you might see as you put that piece of magnesium into the acid? Have you done metals and acids yet? Yeah. Like I think we, my teacher, share like this demonstration and like there's like this loud pop. Loud, Paul. Like you like put like like like I forgot what the name was. I think it was called no calcium. And like you put it into like acid and you put like a boiling tube on top and then you put like this fire inside and there's like this loutop. Okay, so you're talking about the pop test that tests for hydrogen. Yeah, Yeah. So this one's a little bit different. You're just going to see bubbling around your magnesium ribbon and this time you're going to see an increase in temperature. Though the temperature will go up, it will feel warm. Sodium hydrogen carbonate and ethanoic acid. Buzzing and bubbling again, and this time may decrease in temperature, so don't worry, you don't need to remember which ones increase or decrease at the moment. And then burning magnesium, we're going to get that really bright flame, bright White flame, as the magnesium reacts with the oxygen in the air. So are signs of a chemical reaction, color change, effervescence, and that's the proper word for fizzing. Changes in temperature, formation of a precipitate and changing odor. But that's obviously one that you need to be pretty careful with when you're dealing with chemicals. It's not great to be sniffing things in the lab unless your teacher tells you to, of course. Great. Let's finish with this one, and then we'll go on to the second part of the lesson. Or false. Right? Fruit rotting, is that a physical change? Try to complete the table, Linda. Yet obviously, we can't turn back time and we can't make that fruit fresh again. Good. You want to give some of the other examples. Brilliant. Right. Let's go on to the second lesson. And we are looking this time at conservation of MaaS. So what do we mean by that? 我能。Like. Something that like you can't change. Like like the MaaS is going to be like the same at like like the same like throughout the experiment. At the beginning and at the end. Yeah okay, should be. And read this one, please. Learning objective to understand the law of conservation ation of maths so success criteria to investigate conservation of MaaS in a practical investigation to explain what it may appear that MaaS has changed in a chemical reaction to calculate unknown masses using the MaaS ssive reactants of products. Brilliant, right? Let's just do this quickly. So number one. And they are reversible. Yeah, interesting. Mistake there. Ice smelting did you say Yeah? Color change gas temperature change brilliant. Burning wood. A chemil cook reaction. Where reactants are made into a new substance and can and it's like irreversible. Yeah now we get the irreversible word. Or we could talk about it at the atom level. So we could talk about making and breaking bones, rearrangement of atoms to produce new substances. Right. Looking at these chemical reactions, what do we notice? It's like the sum. Like both of them is like the same. Yeah the MaaS of the reactance is equal to the MaaS of products. Now this is coming on the of one of the laws of thermodynamics, where matter cannot be created or destroyed. It just changes form. And that's what conservation of energy is. So we can't actually get rid of anything from the universe. We're just changing the form. So as long as you don't let anything escape into the air when you're doing your reaction, as long as you trap everything, then your actual MaaS should be exactly the same. So it's just about changing. As of the reactance is equal to the total MaaS of the products a draforward. So the products are formed just by rearranging the atoms. We can't create new atoms and we can't lose any. Other than gas or steam escaping into the room. But of course that isn't actually lost, is it? You of it as weighing scales. Alright, so in this practical, again, we can't do this practical. So this is magnesium ribbon and this is a crucible and a lid. Have you seen one of these before? So it looks a little bit like an evaporating basin, but it's not as thick and it's smaller and it's got a little lid on it. So this is something that could be can withstand very, very high temperature. So you wouldn't want to use glass because that might shatter and the lid is airtight, so any gases will not escape. And then we've just got our clay triangle here because the crucible just sits inside that and it stops it wobbling because you don't want to tip it over. Then inside here, this is magnesium ribbon. So the first thing that we have to do is we either weigh the magnesium ribbon separately, record the MaaS, and then weigh the crucible, record the MaaS, or we just put the ribbon inside the crucible and we weigh the whole thing, but we have to weigh beforehand. So there it is with its little lid on. So we measure the MaaS before and we record it. Then we pop it on top of the clay triangle, put the lid on top of the crucible, and you want a blue flame. Now it's going to take quite a lot of heat to get this magnesium burning. So it will take a little while. So you want the hottest flame that you can have. It says after 30s, just gently lift the lid. Now, why are you doing that, do you think? Let the gas like get out. Not let the gas out. No, try again. And we've got a reaction happening, haven't we? So the magnesium has got to be reacting with something. What's it reacting with? Right? It will run out of oxygen if you don't lift that lid and let more in. So the reaction will not go to completion without lifting the lid every now and then to let a bit more oxygen in. Yes, you might lose a little bit of gas, but we can't help that. And of course, do not look at the magnesium, because this will still burn very, very brightly. So to be very careful with this. So keep heating it. Keep lifting that lid every 30s. When you lift the lid and there isn't any kind of glow, you can have a little peek in and you will see weather. All of the magnesium has changed. I'm just gonna to try and get your picture so you can see what it would look like. I did have a video, but I decided it would take a little bit long to watch that. Hmm. Okay. That's probably the best we're going to get. Might have a look in the chat. Can you see that? Yeah. So when you have a little peek in when there's no longer any bright flames, you will see a White powder. Just looking for another Yep, so it will look like this. I think if you look at that one, can you see there's stood a little bit of magnesium at the bottom there that hasn't reacted yet? I think kind of blurry. Okay, I'm just there. I think, Yeah, I can. Can you see the top has gone and not the bottom? Why do you think that might be? Why might the top react first? Because like the oxident refirst, Yeah, absolutely. So this bottom hasn't reacted with the oxygen yet. Maybe they didn't open their lid enough on this one. So this needs to be reheated because it hasn't gone to completion yet. And then where we can see this White ash, if you just tap that gently with a spatula, that would all crummple up and break like in this picture here. So we have got White magnesium oxide powder formed. Sorry, trying to get the right thing opened. What's going on here? It's playing up. It won't open it for me. Says I've got something there, but it's not going to show it. Let me just reopen it. It's already got your screen. Yeah, like there's like nothing. Mmm. Got it. Was hiding. Right. I'm going to give you some results now because obviously, we couldn't do this. And I'm not particularly going to get you to type all of the answers. We can just talk about them to be a little bit quicker. So your results are starting MaaS 25.45. Are you want 25.45 final MaaS 25.85? Right? Don't write anything else. We'll just talk about this to be quick. So do your results show the law of conservation of MaaS? Oh, no, no. Explain why not. Because the starting MaaS was 25.45 and the final one was 25.85. So the MaaS increased good like. But like the law of contivation is like it's equal, it should be the same. Absolutely right. So we are now told that magnesium racks with oxygen in the air to form magnesium oxide. So can you explain now why this did not follow the law of conservation of MaaS and talk about lifting the lid? The magnesium. React with the oxygen when like the air gets in, when it lifts the lead to form like magnesium oxide. And like the oxygen added is like wide, the final MaaS is like greater than the starting MaaS of just like the magnesium, such because we didn't weigh the oxygen each time we lifted the lid, and we added more reactants to the reaction each time we lifted that lid. Yep, brilliant. Okay, let me see what's next, right? I'm going to give you that one for homework. Might give you both of those for homework. Yeah, let's have a little look at this one now. Lighchanges, sorry, I'm just looking for. A sheet that isn't there. Let me just open it up from here. Mystery. 11. Okay. I don't need you necessarily to write anything here. Let's just talk about it. So explain why it does not always appear that the MaaS of a reactant equals the MaaS of the products. The MaaS increased, Yep, because the magnesium reacted with the oxygen. And the MaaS of the oxygen is added to the magnesium. So the turture MaaS increases. And we didn't measure the total MaaS of the oxygen. We measured a little bit of the oxygen that was in the crucible when we measured it at the beginning, but then we kept letting more in. Good. And people forget that, of course, gases do have MaaS. Not a lot of MaaS, but there there is MaaS there. And that will add to the final MaaS of the magnesium oxide, right? What about this one then? So hydrochloric acid, powdered marble, and it tells us a gas escapes. So what happens to the MaaS? It's going to decrease. Because. When like the reaction happened, the gas escaped. They're like the MaaS of the gas is like not in light the that like in like the hydrochloriacid and like the powdered marble anymore. So like the MaaS was like lost. How could we overcome this? How do you think we could trap this gas? Like so the container Yeah so wehave to very quickly drop in the powdered marble, wouldn't we? And then close the stopper. Now we would have the risk of some kind of explosion if it ran out of space in our flask. So we could attach something like a gas syringe, like in the pond weed experiment. Remember when we collected the oxygen in that syringe? So we could attach something like that to collect the gas and stop it from escaping. And. Then what about the last one? So zinc added to sulfuric acid, right? A rubber bong is placed on top of the test tube this time. MaaS stays the same. Because like the reit has a reaction, but like the rubber bunk thing trapped it in, trapped the gas in. So like nothing escaped. So like it should be the same. Yeah, absolutely. Good, let me show you your homework. I'm going to give you two worksheets. Is this the first one? There won't be anything particularly challenging here for you. So just some calculations about conservation of MaaS. That's your first homework. And then your second one is, let me just get the title. You're a. Yes one. Now there is a little bit of repetition of the one that we've just gone through. So those ones will be easy because we've already talked about them. So the zinc, the hydrochloric acid and the magnesium, that's one that we've just done. And then there's two new ones. And that is your second homework, Linda. Okay, what was the last thing you did in your science class at school? Loud pop, loud pops, hydrogen tests, Yeah. Have you done conservation of MaaS? No, no. Okay. All right. So that should do homework. So I'll put those on the chat for you in a minute, and I will see you next. Okay, Linda, bye, bye, bye.