Matter is made up of particles, including atoms, molecules, and ions. Atoms are the smallest particles that make up elements. Matter exists in three states - solid, liquid, and gas - depending on how closely or loosely packed the particles are. In solids, particles vibrate in fixed positions; in liquids, they can move around but remain close together; and in gases, particles are far apart and move quickly in random directions. Phase changes between these states, such as melting, boiling, condensing, and sublimating, involve changes to the energy and movement of particles.

1. CHAPTER 2 The Structure of the Atom

2. What is a matter?

3. Matter is defined as anything that has mass and takes up space .

4. Can you define the word ‘mass’?

5. Mass The mass of an object is the amount of matter the object contains.

6. A golf ball has a greater mass than a tennis ball . The golf ball, therefore, contains more matter.

7. What is matter made up of ?

8. Matter Particles Ions Molecules Atoms is the smallest neutral particles in an element For example : Copper, Cu, Oxygen, O are neutral particles made up of two or more atoms of the same element or different elements Oxygen gas, O 2 Carbon dioxide gas, CO 2 Ions are particles which are positively or negatively charged +ve ions  cations, -ve ions  anions + -

9. matter is made up of particles which are constantly moving and contain kinetic energy The random movement of particles in air is called the Brownian Movement Kinetic Theory of Matter

10. Diffusion is the movement of particles at random from highly concentrated area to a less concentrated area

11. Gases, liquids and solids contain air spaces with gases containing the most and solid containing the least The presence of these empty spaces allow the diffusion of gases, liquids and solids through them > >

12. Do you know why we can smell a durian kept in the corner of a room ? Its smell diffuses rapidly through air which has more empty spaces than liquids and solids

13. Diffusion of particles in a gas, liquid and solid

14. The particles in a solid are packed lightly in a fixed pattern. There are strong forces holding them together, so they cannot leave their positions. The only movements they make are tiny vibrations to and fro.

15. The particles in a liquid can move about and slide past each other. They are still close together but are not in a fixed pattern. The forces that hold them together are weaker than in a solid.

16. The particles in a gas are far apart, and they move about very quickly. There are almost no forces holding them together. They collide with each other and bounce off in all directions.

17. Solid Liquid Gas Melting Freezing Boiling/ Evaporation Condensation Sublimation Sublimation

18. Melting When a solid is heated, its particles get more energy and vibrate more. This makes the solid expand. At the melting point, the particles vibrate so much that they break away from their positions. The solid becomes a liquid.

19. Boiling When a liquid is heated, its particles get more energy and move faster. They bump into each other more often and bounce further apart. At the boiling point, the particles get enough energy to overcome the forces holding them together. They break away from the liquid and form a gas

20. Evaporation Some particles in a liquid have more energy than others. Even when a liquid is well below boiling point, some particles have enough energy to escape and form a gas. It is why puddles of rain dry up in the sunshine.

21. Condensation When a gas is cooked, the particles lose energy. They move more and more slowly. When they bump into each other, they do not have enough energy to bounce away again. They stay close together and a liquid forms. When the liquid is cooled, the particles slow down even more. Eventually they stop moving, except for tiny vibrations, and a solid forms.

22. Sublimation Is a process during which a solid gains enough energy to overcome the forces of attraction between its particles to become a gas, without going through the liquid state, and vice versa

23. Determining the melting point of acetamide Heating of acetamide 3 spatula of acetamide are placed in a boiling tube A 250 ml beaker is filled with water and then placed on a tripod stand The boiling tube is clamped in the beaker and make sure the acetamide is below the water level of the water bath The water bath is heated until reach a temperature about 65 0 C, a stop watch is started and the water is then heated with a low flame The temperature of acetamide is recorded at 30 s intervals until 90 0 C. Make sure the acetamide is stirred continuously during the experiment The result are recorded in a table Cooling of acetamide The boiling tube id removed from the hot water bath using test tube holder It id immediately transferred into a conical flask to be cooled slowly and then the stop watch is started The temperature is recorded at 30 s intervals until 70 0 C Make sure the acetamide is stirred continuously during the experiment The result are recorded in a table