Class 9 Science
Class 9 science important questions with answers pdf
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NCERT questions of science class 9
Important questions Science NCER
Class 9 Study 2022-2023
NCERT Class 9 Science
Name the two important laws established by A.L. Lavoisier and J.L. Proust.
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(i) Law of conservation of mass and (ii) Law of constant proportion.