Page 1 - 3. LESSON NOTES-((3.1 MIND MAP & INTRODUCTION, LAWS OF CHEMICAL COMBINATIONS)L COMBINATIONS).docx
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SAI International School
Lesson Notes
Subject-Chemistry
Ch-Atoms and Molecules
Topic-Mind map and introduction, Laws of Chemical Combination
LESSON NOTE
Laws of Chemical Combination:
The process of combination of two or more elements to form new compounds is
governed by certain laws called laws of chemical combination. These are:
1. Law of conservation of mass (by Lavoisier in 1744):
2. Law of constant proportions (by Proust in 1797):
Law of conservation of mass
• According to the law of conservation of mass, matter can neither be created
nor destroyed in a chemical reaction. It remains conserved.
Or, in a chemical reaction the mass of reactants will be equal to the mass of
products.
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