This document provides an introduction to chemistry concepts including atomic structure, chemical symbols, chemical changes and reactions, chemical equations, types of chemical reactions, and worksheets with questions about chemical formulas, names of compounds and ions, and identifying chemical reactions. It covers topics such as writing formulas, naming compounds, identifying reactants and products, and classifying reaction types. The worksheets contain multiple choice, fill-in-the-blank, and short answer questions testing understanding of these core chemistry concepts.

1. SCIENCE : Std.VII

2. INTRODUCTION

3. CONTD........

4. ATOMIC STRUCTURE

5. CONTD...

6. CONTD..

7. CONTD...

8. BONDS.....

9. CHEMICAL SYMBOLS

28. CHEMICAL CHANGES , REACTION AND
EQUATIONS

29. H2 (g)+O2(g)→H2O(g)

36. C3H8+O2→CO2+H2O :UNBALANCED
LEFT SIDE(NO OF ATOMS) RIGHT SIDE(NO OF ATOMS)
CARBON=3 CARBON=3
HYDROGEN=8 HYDROGEN=8
OXYGEN=10 OXYGEN=10

37. TYPES OF CHEMICAL REACTION

44. ACTIVITY TIME

45. WORKSHEET
 1.WRITE THE SYMBOL FOR THE IONS:
 Copper-
 Ammonium-
 Nitrate-
 Phosphate-
 2.WRITE THE NAME OF THE IONS WHOSE SYMBOL
ARE AS FOLLOWS-
 OH-
 Mg2+
 Fe2+
 Cl-

46. WORKSHEET
 1.Name the reactants and the products in the
following reaction-
 (a)2KOH + H2SO4 K2SO4 +2H2O
 (b)CaCO3 CaO + CO2
 2.JUMBLED FORMULAS-(Write in correct form)
 Lead oxide/ NO2/Ferrous Sulphide/ PbO/Nitrogen
dioxide/FeS

47. WORKSHEET
 1. TICK THE CORRECT OPTION-
 (i)The chemical formula for sodium carbonate is
 (a)NaOH (b)Na2CO3 (c)OHNa (d)NaHCO3
 (ii)The chemical name of CaO is
 (a)Calcium hydroxide (b)Calcium oxygen(c)Calcium
oxide (d)Calcium dioxide.
 2.WRITE THE CHEMICAL FORMULAE OF THE
FOLLOWING COMPOUNDS-
 (i)Aluminium chloride.
 (ii)Carbon monoxide.
 (iii)Baking soda.
 (iv)Nitric acid.

48. WORKSHEET
 NAME THE FOLLOWING REACTIONS-
1)Iron +Oxygen IronOxide.
 2)Sugar Carbon +Water
 3)2NaOH +CO2 Na2CO3 +H2O
 4)BaCO3 BaO+CO2