The Language of Chemistry

1.
A symbol represents a short form of an element.
1. In most cases the first letter of an element was taken as the symbol for that element. Give two examples of the same.
2. In certain cases the first letter along with its small letter from its name were used as the symbols. Give two examples of the same.
3. In some cases the symbols were derived from their Latin names. Name two metals whose symbols are derived from the same.
4. Sulphur is represented by the symbol 'S'. State how the symbol represents the elements
  a] qualitatively [i.e., representation in terms of an atom]
  b] quantitatively, [i.e. representation in terms of weight].
2.
Explain the meaning of the terms in italics given below.
For writing a chemical formula the symbols and the valency of the element or radical should be known :
3.
In hydrogen chloride the valency of the element chlorine is considered as one. Give reasons.
4.
Certain metals exhibit more then one valency hence showing 'variable valency'. Give reasons.

State the valency and name the ion or radical in each of the following cases given below. [The first example is completed for you]

Electrovalent positive ions or radicals		Electrovalent negative ion or radicals
Symbol / valency	Name	Symbol / valency	Name
1. K¹⁺	Potassium	1. Cl^1-	Chloride
2. Na		2. ClO₃
3. H		3. ClO
4. NH₄		4. Br
5. Ca		5. I
6. Mg		6. OH
7. Zn		7. NO₂
8. Ba		8. NO₃
9. Ni		9. HCO₃
10. Co		10. HSO₃
11. Al		11. HSO₄
12. Cr		12. AlO₂
Variable valencies		13. MnO₄
1. Cu¹⁺		14. SO₃
2. Cu		15. SO₄
3. Hg¹⁺		16. S
4. Hg		17. CO₃
5. Fe²⁺		18. O
6. Fe		19. CrO₄
7. Mn²⁺		20. Cr₂O₇
8. Mn		21. ZnO₂
9. Pb2+		22. PbO₂
10. Pb		23. PO₄
11. Pt²⁺		24. N
12. Pt		25. C

State the valency of the elements in the respective compounds in the table below.

22 more answer(s) available.