Intro Quiz: Matter revision (Part 1)

Video: Matter revision (Part 1)

﻿Just take a moment to note down the date and the title so that you can keep all of your notes organised. Hello, I'm Ms. Todd, and welcome to this review lesson of the matter topic. Can you make sure that you've got a nice quiet place to work so that you won't be distracted during the lesson. For today's lesson, you're going to need a pen. So different colour pens or pencils would be preferable 'cause you're going to be making some revision cards. You'll also need a piece of paper. So one sheet of A4 that you can write on. And could you also have one sheet of A4 that you have cut up into squares. These squares will be your revision cards. You will also need a calculator as we're going to do some math skills. If you need to get any of those things, can you please pause now and do so. Resume the lesson when you're ready During today's lesson, we're going to recap particle theory, change of state, density, and diffusion. So we'll start by recapping particle theory. You should recognise these three particle diagrams. They're the solids, liquids, and gases. Let's have a look at how these particles are arranged. In a solid, the particles are ordered and they touch each other. In a liquid, they still touch mostly, but it's a more random arrangement compared with the solid. The particles in a gas are random, and there's lots of space between them. How do the particles move? So let's start by looking at how they move in solids. With a solid, the particles vibrate in place so they don't move around. In liquids, the particles can slide over each other. In a gas, the particles move freely and they move quickly. So how they move has something to do with their forces of attraction. The solid has strong forces of attraction that keep those particles held together. And that is why they vibrate in place. The forces of attraction in a liquid are weaker than in a solid, and this is why they are able to move over each other. Gases have the weakest forces of attraction between their particles. This is why they can move quickly and freely. Solids have a high density, meaning they are more dense than liquids and gases 'cause their particles are more tightly packed. The density of a liquid is lower than in a solid. Gases are the least dense out of solids, liquids, and gases. So what are the forces of attraction like in a solid? Strong or weak? Shout this out for me. Brilliant. They're strong. So strong forces of attraction between the particles in a solid. How do the particles move in a gas? Brilliant. They move quickly. Which state of matter is the most dense? Solids, liquids, or gases. Brilliant. It was solid. How do the particles move in a liquid? Good. They can move around each other or slide over each other. What are the forces of attraction like in a gas? Strong or weak? Brilliant, there are weak forces of attraction in a gas, and that is why gas particles can move quickly and freely. What I'm going to do now is show you how to make some revision cards. So, on your revision cards, on one side, you have your question. So I have chosen, what are the forces of attraction like in a gas? So I would write this question on one side of my card. I would then write the answer on the back. So the forces of attraction in a gas are weak. So on the back I would write weak. I can then make more of these cards and use them to test my knowledge on matter. What is the problem with this revision card here? Good. There is where too much information in that answer. Your revision cards need to have snappy answers that you can recall quickly. What I would like you to do is pause here and on one of the squares of A4s that you cut out, can you make this your first revision card? So you're writing the question on one side and the answer on the other. Good. Now you've made the example one that I gave you. Can you please pause and make each one of these questions into a revision card? So you'll need three squares of paper for this. You write your question on one side and your answer on the other. Excellent. So these are the examples of what your card should look like. On one side you've got your question and the answer on the back. If you need to change any of your answers, can you please pause and change them now so that your revision cards are correct? Good. So now we've looked at particle theory. We'll have a look at changing of state. Take a look at this diagram. This diagram shows us how we get between each stage of matter. So the changes of state. Let's start by looking how do we get from a solid to a liquid. So if we're moving from a solid where the particles are tightly packed and ordered to a liquid where they are mostly touching but have a random arrangement, we will call this melting. So we heat the solid and it melts to a liquid. This is like when an ice cube, which is a solid, will melt into a liquid when you take it out of the freezer. Let's have a look at how we get from a liquid back to a solid. By freezing. So if we have water and we put it in the freezer, it will freeze to an ice cube, which is a solid. Let's look now at how we get from a liquid to a gas. So it's by boiling, although we call it evaporation. So when you heat up a liquid to its boiling point, for example, if you heat water to 100 degrees C, it will start to boil and it will form a gas. So the liquid water will turn into water vapour, which is a gas. If we're going from a gas back to a liquid, this is called condensation. So when you're in the shower, there will be some water vapour in the bathroom. When this water vapour hits your window, which is cold because of the air outside, you will notice condensation form on your window. And this is where the water vapour gas has gone back to liquid water. Let's have a look at how we get from solid straight to gas without going through the liquid phase. So this is called sublimation. Iodine is a solid. If you heat it gently, it will produce fumes. These fumes can be used in forensic science to reveal fingerprints on paper. If we're going from a gas back to a solid without going through the liquid phase, this is called deposition. An example of this could be when frost will form on the surface of a leaf. So when the air becomes cold enough, the water vapour in the air suddenly loses enough thermal energy to become a solid. Let's have a look at heating in more detail. When we heat substances, they often expand. The particles themselves do not expand. What's happened is the particles have gained energy and the space between the particles increases. So the particles haven't expanded, the space between them has got bigger. So we say that the material has become less dense. If enough heat is added to a solid, the particles will gain enough kinetic energy to break away from those attractive forces that hold them together. So remember, we said that solids have really strong forces of attraction. When you heat a solid, they get enough kinetic energy to be able to break away from these attractive forces that are holding those particles together and the substance will melt. So we now say that substance has changed state. It's gone from being a solid state to liquid state. What I would like you to do now is take a look at this diagram and use it to help you explain how increasing the temperature makes a solid melt. Do this on a piece of A4 not on a revision card. Good. So the particles gain energy as they get hotter. As they gain energy, they vibrate more. At the melting point, these vibrations have enough energy to be able to break the forces of attraction that are between those particles and the particles are able to move freely. Let's have a look now at density in more detail. So as you can see here, my solid, my liquid, and my gas are all in a box that is the same size. So this means they are in a fixed volume. Density is the amount of particles in a certain volume. So if you have more particles in that volume, you are more dense. So for example, the solid has the most particles in that given volume. So the solid is the most dense. The gas, however, has the least particles in that given volume. So the gas is least dense. Using density, we can predict if an object will float or sink. The one with the lowest density will float, and the one with the highest density will sink. Let's look at an example. The density of water at 25 degrees is 0.997 grammes per centimetre cubed. These are the units of density. The density of ethanol is 0.789 grammes per centimetre cubed. That means the ethanol is going to float on the water because its density is lower than the water. So remember, the lowest density will float, which in this case is the ethanol, and the highest density will sink. So the ethanol will float on top of the water because it has the lowest density. So again, the density of water at 25 degrees is 0.997 grammes per centimetre cubed. The density of honey is 1.38 grammes per centimetre cubed. So the honey is going to sink in water because its density is higher. So remember, lower density float, higher density sink. What I would like you to do now is fill in the gaps of this sentence onto a sheet of A4. Good, so the oil will float on the water because its density is less than water. We can calculate density by using this equation. Density equals mass divided by volume. Just take a moment to look at those units. So I'm going show you how to calculate density. So we'll start with the wood. So the mass of the wood was 100 grammes. We then divide this by the volume, which was 200, to get our density. So 100 divided by 200 in the calculator is 0.5. So that means the density of wood is 0.5 grammes per centimetre cubed. 'Cause if you notice our units, the mass was given in grammes and the volume in centimetres cubed. So it's grammes per centimetre cubed for our density. Let's have a look now at aluminium. So the mass of aluminium was 40. We then need to divide this by our volume which was 200. 40 divided by 200 in the calculator is 0.2. So the density of aluminium is 0.2 grammes per centimetre cubed. So the mass of the glass was 70 grammes. It was in a volume of 200 centimetres cubed. So 70 divided by 200 on my calculator will give me 0.35. So that means the density of glass is 0.35 grammes per centimetre cubed. Just pause here and onto your sheet of A4 calculate the density of these materials. You also need to make sure that you're giving me your answer to one decimal place. Good. So bricks is 750 divided by 100. And that should have given you an answer of 7.5. Silver is 800 divided by 100. This would have come out to eight on your calculator, but I asked you for your answers to one decimal place. So it's 8.0 . Water had a mass of 100 grammes. So we divide this by the volume which is also 100. 100 divided by 100 would have gave you an answer of one. But again, I asked for your answers to one decimal place. So it should be 1.0. All of these materials were in the same volume. So we can have a look at their density and compare them. So as you can see, the silver was the most dense, followed by the bricks, and then the water. Let's now have a look at diffusion. Diffusion is the passive movement of particles from an area of higher concentration to an area of lower concentration. For the following images, I would like you to tell me which way the substances will diffuse. Remember, we're going from a high concentration to a lower concentration. So how will these substances diffuse? From left to right, or right to left? Good. Left to right. 'Cause there are more particles on the left, so they will diffuse to the lower concentration on the right. How will these particles diffuse? Right to left, or left to right? Good, they will go from right to left because there is a higher concentration of particles on the right, so they will move to the lower concentration on the left. So there are two factors that can affect diffusion. The concentration gradient. The concentration gradient is the difference between the number of particles on each side. So the higher the difference between the number of particles, the faster diffusion. And temperature. So as we increase the temperature, the particles gain more kinetic energy. So the rate of diffusion will be faster. So increase in temperature increases the rate of diffusion. So we've just said that the concentration gradient is the difference between the particles on each side. So if we look at A, we've got five particles on the left and four particles on the right. So that means the difference in the number of particles is one. If we look at B, there are five particles on the left and two particles on the right. So that means the difference between the particles is three. That means that B will have a faster rate of diffusion because the concentration gradient is steeper. So the bigger the difference between the particles on each side, the steeper the concentration gradient, and this means faster diffusion. So here, B will have faster diffusion as the concentration gradient is steeper than A. Can you have a go at this one for me? Which one is going to have faster diffusion, A or B? Brilliant, A. Because A has a steeper concentration gradient. What about this one? Which one will diffuse faster, A or B? Brilliant B. 'Cause B has the steeper concentration gradient. So there is a bigger difference in the number of particles on each side. What I would like you to do now is pause here and on your sheet of A4, can you answer these questions for me? Good. So look at your answers against the answers on the screen. If you need to make any changes, can you please pause and do this now. If you would like to share any pictures of your revision cards that you've made today, please ask your parents or carer to share your work on Instagram, Facebook, or Twitter, tagging @OakNational and #LearnWithOak. So that brings us to the end of today's lesson. And I'd just like to say a really big thank you for all of the fantastic effort that you've put in today. You've made some great revision cards and answered some tough questions. Please remember to go and complete the exit quiz, and have a lovely rest of...

Worksheet: Matter revision (Part 1)

Exit Quiz: Matter revision (Part 1)

Completed: Matter revision (Part 1)

In this lesson we will review the Matter topic and make some revision cards that we can use to get exam ready.

Science

Matter revision (Part 1)

Introductory Quiz

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