Why did you choose this one? This is why the gaseous state of water is sometimes called water vapour. Why did the water push out of the bottle when it turned to ice? If you have a pipette, use it to carefully layer the liquids. Particle Model of Matter - Gas Lesson predominantly based on the AQA scheme of work. Record the time when the first learner puts up his/her hand to indicate that they can smell the vanilla essence. What is the volume of milk in the carton and the volume of juice in the bottle in the following photo? Blow up the balloon until it is the size of an orange. It can be relaxed somewhat by stretching the balloon before blowing into it, but the first one or two 'blows' will require some effort. If you measured the mass of each liquid, write the mass in brackets after each label. They have the same volume of 100 mL. Mercury is the only metal that is a liquid at room temperature. A possible method which learners might come up with, and which you can follow in class, is as follows: (The steps in a method must be numbered). Note: If doing the practical demonstration, get the learners to make a prediction in the time that it takes for the ball to cool down. This assumption allows the use of ideal gas laws which greatly simplifies calculations. If so, what? The honey is the most dense as it is at the bottom; the rubbing alcohol is the least dense as it floats on top of the other layers. But this is beyond the scope of this discussion here for the learners. Do you see how we have used the particle model of matter to explain the properties of solids that we can observe? When a solid is heated it will change to a liquid (in a process called melting) and, when heated further, the liquid will change to a gas (in a process called evaporation). How can materials be made to change their state? You need to write the method for this investigation. Their particles are free to move around, filling the spaces left by other particles. Answer B would now represent the thermometer at a higher temperature of 30°C as the particles have gained more energy and therefore moving at greater speeds so they move further apart and the liquid expands. That means that 10 cm x 10 cm x 10 cm = 1000 cm3 which equals 1000 ml or 1 litre. 1 Look at the following images of sodium chloride (table salt). The mass of an object or a substance tells us how much matter it consists of. Remember to write your observations below. The objects drop to the different levels depending on their densities. They should be spread more or less evenly amongst the colourless particles. You can also point out that they also compared materials in different states, and they also compared two solids, namely sand and flour. The higher the temperature of the liquid, the faster it will evaporate. So by increasing the temperature of the system, the particles move faster; the higher the temperature, the higher the average energy. Gas particles move very fast, much faster than in solids and liquids. The image of Boyle's equipment shows some of the exotic tools used by Boyle during his study of gases. is the force measured in Newtons, When a substance cools (energy is removed), the particles in that substance will slow down and move closer together. These events are also described by particle theory. By giving the vibrating particles in a solid more energy, their vibrations will become more and more vigorous, until the solid particles are able to shake themselves loose from their fixed positions. Note: If the bag is strong it may not be possible to pop it by blowing into it, because humans cannot blow with much force. combustor sections – 1300 K), the complex fuel particles absorb internal energy by means of rotations and vibrations that cause their specific heats to vary from those of diatomic molecules and noble gases. The pressure caused by a gas can be calculated using the equation: A person standing in a room full of air is constantly being hit by the particles of the gases that make up the air . Kinetic energy added (endothermic process) to gas particles by way of collisions produces linear, rotational, and vibrational motion. The particles are close together but they can move around. A pure gas may be made up of individual atoms (e.g. Evaporation occurs only on the surface of the liquid, while boiling occurs throughout the entire liquid. London WC1R 4HQ. If the temperature was raised and the thermometer read 30°C, which circle would now best represent the particles in the liquid of the thermometer? We will make a simple comparison of the mixing rates, by seeing how long it takes each to mix under two different sets of conditions. In solids these movements are limited to vibrations, but in liquids and gases the particles have more freedom. Think of a bag of cake flour. What are your conclusions? Use the same amount of each liquid.  Gay-Lussac credited Charles' earlier work by naming the law in his honor. Smaller items expand less because there is less matter that can expand. This explains why the particles in gases are not neatly arranged. You can choose your own column and row headings. When we measure the mass of small objects or small amounts of matter we often measure in grams (g) or even milligrams (mg). What will happen if a gas particle collides with an air 'particle'?). Explain your answer. When they are no longer holding hands and are able to move around, this represents the liquid state. But what about liquids? Particles in solids are held together very closely. 7 we learnt about different kinds of mixtures. The speed at which particles diffuse depends on several factors, namely: Particles diffuse because they are in constant motion. When describing a container of gas, the term pressure (or absolute pressure) refers to the average force per unit area that the gas exerts on the surface of the container. In this activity these ideas are revisited and expanded upon, with the particle model as frame. The ideal gas law does not make an assumption about the specific heat of a gas. Do not tell the learners that the 'mystery liquid' is vegetable oil but rather let them try to identify it. If the gas is cooled, the particles will move more slowly, because they will have less energy. Mass is measured in kilograms (kg). Oil does not dissolve in water. cooking pots. If you have access to a scale, measure the mass of each cup with a different liquid. Particles in a: gas vibrate and move freely at high speeds. You do not have to measure their masses on a scale. Which material has the highest density: sand, flour, water or air? This means the rate of diffusion is much slower in liquids than in gases, because the particles of a gas are further apart and collide much less. Is this correct? The particle model of matter is one of the most useful scientific models because it describes matter in all three states. The methods of storing this energy are dictated by the degrees of freedom of the particle itself (energy modes). You can do a practical demonstration of this in class with your learners.