Changes in Matter

2. Changes in Matter Please write into notebook  • CH 4

3. 4.0 Types of Changes: Please write into notebook  Three Types of Changes Nuclear Transformations Physical Change Chemical Change

4. 4.1 Physical Change: Please write into notebook  • Does not change the chemical composition or the nature of a substance • Process is easily reversible • Ex. Crumpling & smoothing out paper • Ex. Freezing water and thawing ice • Ex. Sublimation – from solid to gas (ex. dry ice (CO2) or iodine)

5. Tells you a physical change occurred • Key Words: • Crush/Pulverize • Melt • Evaporation (lg) • Condensation (gl) • Solidification(ls) • Sublimation (sg) • Dissolve (dissolution) Please write into notebook 

6. 4.2 Chemical Changes: Please write into notebook  • Changes the chemical composition or make-up of the substance • New substances are formed with new properties • Not easily reversible (Reversible only through chemical means or reactions) Rust

7. Tells you a chemical change occurred Please write into notebook  Signs of Chemical Changes: • Formation of a gas • Formation of a precipitate • Change in colour • Production of heat &/or light • Increase or decrease in mass

8. 4.3 Nuclear Transformations: Please write into notebook  • The particles in the nucleus are rearranged. • New elements are created! • Fission = nucleus is split to make 2 or more lighter nuclei • Fusion = 2 small nuclei combine to form one heavier nuclei

10. 4.4 Reactions Please write into notebook  Chemical reactions can be represented symbolically with chemical equations eg. Meaning: 2 molecules of water (H2O) combine to make 2 molecules of hydrogen gas (H2 ) and 1 molecule of oxygen gas (O2). 2H2O (l) → 2H2 (g) + O2 (g)

12. s = solid l=liquid g=gas aq=aqueous (dissolved) Please write into notebook 

13. 2H2O (l) → 2H2 (g) + O2 (g) Please write into notebook  The particle model uses spheres to represent the individual atoms. H = O = +

14. Particle Model for burning natural gas.

15. Types of Chemical Change • Synthesis (come together) • Decomposition (go apart) • Precipitation (solid is formed) • Acid-Base neutralization • Oxidation * • Combustion * • Cellular respiration • Photosynthesis

16. 4.5 Oxidation Please write into notes • Materials oxidize when they react with oxygen in the air • Rusting (corrosion) is a form of oxidation • Iron in air will form iron oxide (rust) 4Fe + 3O2 2Fe2O3

17. Iron Oxide (Rust)

18. Copper Oxide

19. 4.6 Speed of oxidation Please write into notes Slow Down Speed up Air Light Water Salt • Galvanize the metal (coat in Zinc) • Oil coating (rust proofing) • Water proofing • Preservative

20. 4.7 Combustion Please write into notes • A form of oxidation that releases a large amount of energy • Burning wood, • Cellular respiration • Burning fossil fuels Internal Combustion engine 

21. 3 conditions necessary for combustion Please write into notes • Ignition temperature: minimum temperature needed for combustion to start. • Oxidizing agent: causes the fuel to react (02 in the air is most common) • Fuel: substance that is holding onto chemical energy in its bonds (wood, propane, oil, gas etc.)

22. Triangle of Fire Please put triangle into notes Combustion will continue until you run out of one (or you have very little left)!

23. 3 types of combustion Please write into notes fire, explosion, car engine 1-Rapid:

24. 3 types of combustion Please write into notes 1-Rapid: fire, explosion, car engine 2-Slow: decomposition, fermentation, corrosion

25. 3 types of combustion Please write into notes 1- Rapid: fire, explosion, car engine 2- Slow: decomposition, fermentation, corrosion 3-Spontaneous: ignites without any outside energy source (eg: some forest fires, oil coated rags, etc.) linseed oil link

26. Glucose + oxygen  carbon dioxide + water + energy