Solids, liquids and gases

1. Solids, liquids and gases Miss Jan

2. Solids, liquids, and gases SLOs: • revise the particle theory of matter • understand that particles can be atoms, ions, or molecules • recognise physical and chemical changes

3. Think, pair and share • Think about what you learnt about particles (particle theory, particle movement in liquids, solids, and gases) last year. • Discuss with your neighbour • Share some ideas with the class

4. The Particle Theory of Matter 1. Matter is made up of tiny particles 2. Particles of Matter are in constant motion. 3. Particles of Matter are held together by very strong electric forces 4. Temperature affects the speed of the particles.  The higher the temperature, the faster the speed of the particles.

5. Close togetherRegular pattern Far apartRandom Move around each other

6. 1 3 2 4 5 6 Reverse sublimation = Deposition

7. Safety precautions/reminders • Always wear safety glasses when working with flames or chemicals • Tie back long hair • Put chairs and bags under tables • Use heat mats • Always supervise a Bunsen • Clean up spills quickly

8. Workbook page 2 experiments Remember to answer these three key questions! • What do the substances look like at the start? • What happens to them during the experiment? • What do the substances look like at the end?

9. Workbook page 2 experiments • Experiment A and C only A. Hold a small piece of Mg in a pair of tongs in a Bunsen flame. C. Put some small piece of Zn in a test tube with 3 cm of sulfuric acid. Hold your thumb over the top to collect the gas. Then put a burning match by your thumb and release the gas.

10. Answers A Magnesium • Before heating, magnesium is a grey metal. • When heated in the Bunsen flame, the magnesium catches fire and burns with a bright white flame. • At the end, a crumbly white powder is left.

11. C Zinc and sulfuric acid • Zinc is a heavy grey metal. Dilute sulfuric acid is a colourless liquid. • When they are mixed together, they produce bubbles of gas. The gas burns with a shrill pop when ignited. • At the end, the zinc has all gone and a colourless liquid is left.

12. Continue answering questions on page 2 - 3 • You may use NMS 2 page 2 for help if needed

13. NMS 2 – complete page 3 questions What’s the Matter – p. 3 1. In solids, the particles are packed close together and don’t move around. In liquids, the particles are packed close together but can move around slowly. In gases, the particles are far apart and move around rapidly throughout the gas.

14. 2. When a substance is heated, usually: a solid melts  liquid then liquid boils  gas. When a substance is cooled, usually: a gas condenses  liquid then liquid freezes  solid

15. 3. Physical changes do not produce new substances. E.g. State changes. Also include changes in: sample size (cutting up a solid) shape (bending a solid or putting a liquid or gas into a different shape of container) pressure or temperature; purity (when two substances are mixed). Chemical changes produce new substances. Examples are given on page 3.

17. 5.

18. 6. When objects are cooled they usually get smaller. (See what happens if you blow up a balloon and then put it in the freezer). When objects are heated they usually get larger. This time blow up the balloon just a bit and then heat it up by putting it in a beaker of hot water. (Size changes are most noticeable with gases, and less so with liquids and solids)