Page 230 - ICSE Chemistry 8

5. LANGUAGE OF CHEMISTRY

Valency of Elements

Monovalent Trivalent Tetravalent Pentavalent
Divalent elements
elements elements elements elements

Chemical Equation

Unbalanced Balanced
equation equation

6. CHEMICAL REACTIONS

Chemical Reactions

Characteristics Conditions Necessary Types

Evolution of gas Close contact Combination Reaction

Change of colour Presence of solution Decomposition Reaction

Formation of precipitate Heat energy Displacement reaction

Change of state Light energy Redox Reaction

Change in energy Electricity Double displacement Reaction

Pressure

Catalyst
Precipitation Neutralisation
reaction reaction

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