Chemistry

Atoms and Molecules

Valencies of Some Common Metal Elements Valencies of Some Common Non-Metal Elements

Element	Symbol	Valency
Lithium Sodium Potassium Silver Copper Mercury Magnesium Calcium Zinc Iron Aluminium	Li Na K Ag Cu Hg Mg Ca Zn Fe Al	1 1 1 1 1 and 2 1 and 2 2 2 2 2 and 3 3

Element	Symbol	Valency
Hydrogen Fluorine Chlorine Bromine Iodine Oxygen Sulphur Nitrogen Phosphorus Carbon	H F Cl Br I O S N P C	1 1 1 1 1 2 2 3 3 4

Though the usual valency of sulphur is 2 as shown in the second table, it also shows valencies of 4 and 6 in some compounds. For example, the valency of S in

H

₂S is 2,in

SO

₂ is 4 and in SO3 is 6.Similarly,though the usual valency of nitrogen and phosphorus is 3, they also show a valency of 5 in some compounds.Please note that an element having a valency of 1 is called monovalent ; valency 2 elements are called divalent ; valency 3 elements are called trivalent ; valency 4 elements are called tetravalent ; valency 5 elements are called pentavalent whereas the valency 6 elements are called hexavalent. Dear student, we have given so many details here so that you are able to write the formulae of various compounds easily and correctly. We will now give the methods of writing the formulae of compounds.

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Notes

Atoms and Molecules - Notes

1. Drawbacks of Dalton’s Atomic Theory

2. Monovalent Cations (Cations Having a Valency of 1+)

3. Divalent Cations (Cations Having a Valency of 2+)

4. Trivalent Cations (Cations Having a Valency of 3+)

5. Dalton’s Symbols of Elements

6. an example, let us give the significance of symbol C

7. Formulae of Some Molecular Compounds

8. An Important Discussion

9. Molecular Formulae of Some Common Elements

10. Explanation of the Law of Conservation of Mass

11. 2. A Negatively Charged Ion is Known as Anion

12. Molecules

13. As an example, let us give the significance of the formula H₂O

14. Simple Ions and Compound Ions (Polyatomic Ions)

15. Molecules of Compounds

16. Formulae of Elements

17. Chemical Formulae

18. Some Ionic Compounds

19. Symbols of Elements

20. Molecular Mass

21. Gram Atomic Mass And Gram Molecular Mass

22. Atoms

23. Formulae of Compounds

24. Formula Mass

25. Atoms, Molecules and Ions

26. 1. Molecules of Elements

27. Mole of Atoms

28. 1. A Positively Charged Ion is Known as Cation

29. Ions

30. Mole of Molecules

31. Dalton's Atomic Theory

32. Laws Of Chemical Combination

33. Calculation of Molecular Mass

34. Divalent Anions (Anions Having a Valency of 2-)

35. Molecular Masses of Some Common Elements

36. Some Common Ions

37. Explanation of the Law of Constant Proportions

38. John Dalton

39. Significance of the Formula of a Substance

40. Formula Unit of Ionic Compounds

41. Ionic Compounds

42. Symbols Derived from Latin Names of the Elements

43. Modern Symbols of Elements

44. Atomic Mass Of An Element

45. Valencies of Some Common Metal Elements Valencies of Some Common Non-Metal Elements

46. Atomic Masses of Some Common Elements

47. Writing Of Formulae Of Molecular Compounds

48. Laws Of Conservation of Mass

49. Problems Based On Moles Of Atoms

50. Writing Of Formulae Of Ionic Compounds