iGCSE Chemistry Lesson 1 - Atoms into ions.pptx

IGCSE

1. How do atoms become ions? Do now: Draw the electronic structures of: Period 2: Li +1 ,Be, C, O -2 Period 3: Na, Mg +2 , S, Cl -1 What do you notice?

2. Losing electrons to form positive ions Na Na 2,8,1 + [ 2,8 ] + Outermost shell only drawn

3. Gaining electrons to form negative ions Outermost shell only drawn Cl Cl 2,8,7 - [2,8,8] -

4. Transfer of electrons

5. Ionic bonding So when sodium reacts with chlorine, each sodium atom loses an electron and each chlorine atom gains an electron. Why would they form ions?

6. Ionic bonding So when sodium reacts with chlorine, each sodium atom loses an electron and each chlorine atom gains an electron. They both form stable ions.

7. Drawing ions Apply what you have just learnt about sodium chloride to other ionic compounds. Group 1 elements lose 1 electron Group 2 elements lose 2 electrons Group 6 elements gain 2 electrons Group 7 elements gain 1 electron EXTENSION TASK : ON THE DIAGRAMS YOU HAVE DRAWN, WRITE THE ELECTRON CONFIGURATIONS FOR THE ATOMS AND THE IONS.

8. GAIN? LOSE?

9. LOSE 2 ELECTRONS

10. GAIN? LOSE?

11. GAIN 2 ELECTRONS

12. GAIN? LOSE?

13. GAIN 1 ELECTRON

14. GAIN? LOSE?

15. GAIN 3 ELECTRONS

16. GAIN? LOSE?

17. LOSE 3 ELECTRONS

18. GAIN? LOSE?

19. LOSE 1 ELECTRON

20. Na 11 23 Sodium Atom 11 Electrons (-) 11 Protons (+) 12 Neutrons Neutral Charge Na 11 + 23 Sodium Ion 10 Electrons (-) 11 Protons (+) 12 Neutrons Positive Charge Lose electron = Positive Charge Ion Fluorine Ion 10 Electrons (-) 9 Protons (+) 10 Neutrons Negative Charge F 9 - 19 F 9 19 Fluorine Atom 9 Electrons (-) 9 Protons (+) 10 Neutrons Neutral Charge Gain electron = Negative Charge Ion Na F ISOTOPES Same Number of Protons and Electrons Different Number of Neutrons Cl Cl Ag Ag 35 37 107 109 75% 25% Relative Atomic Mass ( RAM) = (35 x 75 ) + (37 x 25) / 100 = 35.3 Relative Atomic Mass ( RAM) = 107 + 109 / 2 = 108 50% 50% Help sheet!

21. Task Complete the worksheet.

22. Use green pen

23. Use green pen

24. Exam question

25. Exam questions

26. Exam question

27. Exam question