1.  Chemical reaction: It is a process that involves breaking the existing bonds in the reactant molecules and forms new bonds in the products.  Importance of chemical reactions: 1. Burning of car fuel in the car engine. 2. Plants make their food through photosynthesis process. 3. Medicine, fertilizers, artificial fibers are examples of outcomes of some chemical reactions. 1

2. 1. Thermal decomposition reactions. 2. Substitution reactions. 3. Oxidation reduction reactions. 2

3.   3

4. 2 HgO 2Hg + O 2 4

5. Cu(OH) 2 CuO + H 2 O blue black 5

6. CuCO 3 CuO +CO 2 Green black 6

7. CuSO 4 CuO + SO 3 blue black 7

8. 2NaNO 3 2 NaNO 2 + O 2 8

9.  Air bags: They are considered one of the most important safety means in cars at emergencies. 9

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11.  They are the reactions which depend on the activity of the metals, where the element which is more active substitutes (replaces) the less active one in its compounds.  The activity of metals can be determined by using the “chemical activity series” 11

12.  It is the arrangement of the metals in an descending order according to their chemical activity. 12

13. 13

14. 1.Simple substitution reactions 2. Double substitution reactions 14

15. + + Types of simple substitution reactions A. Metal substitutes Hydrogen of acid or water. B. Metal substitutes another metal in its salt solution. 15

16. 2Na +2 H 2 O 2NaOH + H 2 16

17.  Zn + 2HCl ZnCl 2 +H 2 17

18.  2Al + 6HCl 2AlCl 3 +3H 2 18

19.  Mg + CuSO 4 MgSO 4 +Cu 19

20.  booklet page 13 20

21. ++ 21

22.  1. Reaction between acid and alkali ( Neutralization reaction)  2. Reaction between acid and salt.  3. Reaction between two salt solution. 22

23.  Acid + Alkali Salt + Water  HCl + NaOH NaCl + H 2 O 23

24. NaCO 3 + 2HCl 2NaCl + H 2 O+CO 2 3. Reaction between two salt solution. NaCl +AgNO 3 NaNO 3 +AgCL 24

25.  Booklet page 14 25