1. ART IS I; SCIENCE IS WE.
- CLAUDE BERNARD -

2. WHAT ARE VALENCE ELECTRONS?

3. WHAT ARE VALENCE ELECTRONS?
VALENCE ELECTRONS ARE THE ELECTRONS IN THE OUTER SHELL OF AN ATOM.

4. WHY ARE VALENCE ELECTRONS IMPORTANT?

5. WHY ARE VALENCE ELECTRONS IMPORTANT?
THEY DETERMINE HOW THE ELEMENT WILL REACT CHEMICALLY.

6. HOW CAN YOU DETERMINE HOW MANY VALENCE ELECTRONS AN ATOM HAS?

7. HOW CAN YOU DETERMINE HOW MANY VALENCE ELECTRONS AN ATOM HAS?
YOU CAN TELL HOW MANY OUTER ELECTRONS OR VALENCE ELECTRONS AN ATOM HAS BY LOOKING AT WHAT COLUMN (FAMILY OR GROUP) THE ELEMENT IS IN.

8. WHAT IS THE OCTET RULE?

9. WHAT IS THE OCTET RULE?
THE MAXIMUM NUMBER OF ELECTRONS AN ATOM CAN HAVE IN THE OUTER SHELL IS EIGHT WITH THE EXCEPTION OF THE 1ST SHELL, AND THAT IS TWO.
THIS REPRESENTS A STABLE CONFIGURATION.

10. ATOMS OF METALLIC ELEMENTS TEND TO LOSE THEIR VALENCE ELECTRONS, LEAVING A COMPLETE OCTET IN THE NEXT LOWEST ENERGY LEVEL (SHELL).
ATOMS OF SOME NONMETALLIC ELEMENTS TEND TO GAIN ELECTRONS TO ACHIEVE A COMPLETE OCTET.

12. WHEN AN ATOM LOSES ELECTRONS, WHAT KIND OF AN ION DOES IT BECOME?

13. WHEN AN ATOM LOSES ELECTRONS, WHAT KIND OF AN ION DOES IT BECOME?
AN ATOM’S LOSS OF VALENCE ELECTRONS PRODUCES A CATION, A POSITIVELY CHARGED ION.

14. WHAT KIND OF AN ION DOES AN ATOM PRODUCE WHEN IT GAINS ELECTRONS?

15. WHAT KIND OF AN ION DOES AN ATOM PRODUCE WHEN IT GAINS ELECTRONS?
AN ATOM’S GAIN OF VALENCE ELECTRONS PRODUCES AN ANION, A NEGATIVELY CHARGED ION.

16. HOW MANY VALENCE ELECTRONS DO METALS USUALLY HAVE?

17. HOW MANY VALENCE ELECTRONS DO METALS USUALLY HAVE?
MOST METALS HAVE THREE OR FEWER VALENCE ELECTRONS.

18. HOW MANY VALENCE ELECTRONS DO NONMETALS USUALLY HAVE?

19. HOW MANY VALENCE ELECTRONS DO NONMETALS USUALLY HAVE?
MOST NONMETALS HAVE FIVE OR MORE VALENCE ELECTRONS.

20. DO IONIC COMPOUNDS HAVE AN ELECTRICAL CHARGE?

21. DO IONIC COMPOUNDS HAVE AN ELECTRICAL CHARGE?
NO. ALTHOUGH THEY ARE COMPOSED ON IONS (CHARGED PARTICLES), IONIC COMPOUNDS ARE ELECTRICALLY NEUTRAL (SAME NUMBER OF POSITIVE CHARGES AS NEGATIVE CHARGES).

22. WHAT KIND OF FORMULAS DO WE WRITE FOR IONIC COMPOUNDS?

23. WHAT KIND OF FORMULAS DO WE WRITE FOR IONIC COMPOUNDS?
TRUE MOLECULES DON’T EXIST IN IONIC COMPOUNDS. WHEN WE WRITE FORMULAS, WE WRITE THE SIMPLE OR EMPIRICAL FORMULA – THE SIMPLEST WHOLE NUMBER RATIO OF ATOMS IN THE COMPOUND.

25. NAME THREE PROPERTIES OF IONIC COMPOUNDS.

26. NAME THREE PROPERTIES OF IONIC COMPOUNDS.
MOST ARE CRYSTALLINE SOLIDS AT ROOM TEMPERATURE.
MOST HAVE HIGH MELTING POINTS.
WHEN DISSOLVED IN WATER OR MELTED, THEY CONDUCT ELECTRICITY.

27. WHICH OF THE FOLLOWING IS NOT AN IONIC COMPOUND?

28. WHICH OF THE FOLLOWING IS NOT AN IONIC COMPOUND?KF
Na2SO4
SiO2
Na2O

29. WHICH OF THE FOLLOWING IS NOT AN IONIC COMPOUND?KF
Na2SO4
SiO2
Na2O

30. HOW MANY VALENCE ELECTRONS DOES ARSENIC HAVE?5 3 4 2

31. HOW MANY VALENCE ELECTRONS DOES ARSENIC HAVE?5 3 4 2

32. WHICH FORMULA IS INCORRECT?
Magnesium iodide, MgI2
Potassium selenide, K2Se
Calcium oxide, Ca2O2
Aluminum sulfide, Al2S3

33. WHICH FORMULA IS INCORRECT?
Magnesium iodide, MgI2
Potassium selenide, K2Se
Calcium oxide, Ca2O2
Aluminum sulfide, Al2S3

34. STATE THE NUMBER OF ELECTRONS EITHER LOST OR GAINED IN FORMING EACH ION.

35. STATE THE NUMBER OF ELECTRONS EITHER LOST OR GAINED IN FORMING EACH ION.
Br-
Na+
As-3
Ca+2 H-

36. STATE THE NUMBER OF ELECTRONS EITHER LOST OR GAINED IN FORMING EACH ION.
Br- - one gained
Na+ - one lost
As-3 – three gained
Ca+2 – two lost
H- - one gained

37. HOW MANY VALENCE ELECTRONS DOES EACH ATOM HAVE?
NITROGEN
PHOSPHORUS
LITHIUM
BARIUM
BROMINE
CARBON

38. HOW MANY VALENCE ELECTRONS DOES EACH ATOM HAVE?
NITROGEN - 5
PHOSPHORUS - 5
LITHIUM - 1
BARIUM - 2
BROMINE - 7
CARBON - 4

39. WRITE THE FORMULAS FOR THE IONS FORMED WHEN THE FOLLOWING ELEMENTS ARE INVOLVED IN AN IONIC REACTIION.
ALUMINUM
BERYLLIUM
IODINE
SULFUR
BARIUM

40. WRITE THE FORMULAS FOR THE IONS FORMED WHEN THE FOLLOWING ELEMENTS ARE INVOLVED IN AN IONIC REACTIION.
ALUMINUM – Al+3
BERYLLIUM – Be+2
IODINE – I-
SULFUR – S-2
BARIUM – Ba+2