This document discusses the kinetic model of matter and the states of matter. It explains that matter is made of tiny particles called atoms and molecules that are in constant motion. There are three states of matter - solids have a fixed shape and volume, liquids have a fixed volume but can flow and take the shape of containers, and gases have no fixed shape or volume and their particles are far apart. The document describes how temperature, pressure, and volume are related based on the kinetic model, such as how increasing temperature causes particles to move faster and increase pressure.

1. Kinetic Model of Matter Kinetic Model of Matter

2. State of Matter Matter is made up of a tiny particles called atoms and molecules . These particles are much too small to be seen by human eyes. Ice, water and steam are three different states of matter of the same material. The three states of matter are called solid, liquid and gas. Kinetic Model of Matter

3. Solid Properties Fixed shape and fixed volume Not compressible Does not flow easily Distance between molecules The molecules are arranged close together in a regular pattern. Solids cannot be compressed because the molecules are arranged closed together and there is little space between them. Kinetic Model of Matter

4. Forces between molecules/ Motion of the molecules There are balanced forces between the molecules which hold them in fixed positions. The molecules can only vibrate about their fixed positions alternately attracting and repelling one another. The strong attractive forces prevent the molecules from leaving their positions while the repulsive forces which act when they are too close to each other prevent them from collapsing. This explains why a solid has a fixed shape and a fixed volume. When a solid is heated, the molecules gain energy and vibrate. The separation between molecules increases slightly and the solid expands. Kinetic Model of Matter

5. Liquid Properties Fixed volume but no fixed shape Assumes the shape of the container which it occupies Not easily compressible Flows easily Distance between molecules The molecules are not arranged in a regular pattern and are slightly further apart than in solids. Liquids cannot be compressed as the molecules are close together and there is little space between them. Kinetic Model of Matter

6. Forces between them/ Motion of the molecules The molecules also vibrate to and fro, alternately attracting and repelling one another with forces which can be just as strong as those in solid. Though there is still forces between the molecules, they are not held in fixed position. Because of this, the molecules move among one another throughout the liquid. That is why liquids flow and take the shape of their container. The attractive forces between the molecules make it difficult for the molecules to leave the liquid and thus liquids have a definite volume. When a liquid is heated the molecules vibrate and move about vigorously. Thus the liquid expands slightly only to a very slight extent. Kinetic Model of Matter

7. Gas Properties No fixed shape and no fixed volume Assumes the shape and volume of its container Highly compressible Flows easily Distance between molecules The molecules are far apart. A gas can be compressed because the molecules are sparse and there is a lot of space between them. Kinetic Model of Matter

8. Forces between them/ Motion of the molecules The molecules move randomly at high speed, colliding with one another and with the walls of the container. The intermolecular forces act only at moments of collision. Otherwise, the molecules are so far apart the intermolecular forces become negligible. Therefore, a gas is free to fill a container completely. Kinetic Model of Matter

9. Brownian Motion Brownian motion is named after Scottish botanist Robert Brown who first observed it in 1827. He used a microscope to study tiny grains of pollen suspended in water. He noticed that the grains were constantly moving in a random manner. Kinetic Model of Matter

10. Kinetic Model of Matter Brownian motion can also be seen when using a microscope to look at smoke particles floating in the air. The smoke particles are seen to move continuously and haphazardly.

11. Kinetic Model of Matter He suggested that the irregular or random motion of smoke particles was the result of smoke particles being hit by unseen, fast moving air molecules. Hence Brownian motion provides evidence of the movement of molecules. In 1905 Einstein was able to explain how Brownian motion takes place.

12. Kinetic Model The kinetic theory of matter states that all matter is made up of a large number of tiny atoms or molecules which are in continuous motion. The existence of particles in continuous motion has been demonstrated by Brownian motion and diffusion. Kinetic Model of Matter

13. Motion of Molecules and Temperature In Brownian motion demonstration we can see that when the temperature is higher, the motion of smoke particles in the air become more vigorous. This is because the surrounding air particles are moving faster and hitting the smoke particles more frequently and with greater force. When temperature increases, thermal energy is transferred to the molecules and the molecules gain kinetic energy. Hence the molecules move faster. Kinetic Model of Matter

14. Motion of Molecules and Pressure When randomly moving gas molecules hit the wall of a container they exert a force on the wall. As the pressure is defined as force per unit area, the force acting in the container gives rise the gas pressure. Kinetic Model of Matter

15. Pressure against Temperature For fixed mass of gas at constant volume; As temperature of gas in container increases, the molecules move faster and hit the walls more frequently and more violently . Gas pressure increases with gas temperature and vice versa at constant volume. Kinetic Model of Matter

16. Volume against Temperature When temperature of the gas container increases, the molecules move faster and hit the walls more frequently and with greater force . This causes the pressure to increase. At constant pressure, the volume of gas increases with increasing temperature and vice versa. Kinetic Model of Matter

17. Pressure against Volume If we half the volume of container, the number of molecules hitting the wall in one second will also be double . At constant temperature, gas pressure increases when volume decreases. Kinetic Model of Matter