A. Law of conservation of mass
A.
B. Law of definite proportions
B.
C. Law of multiple proportions
C.
D. Avogadro's law
D.
Correct Answer: B
সঠিক উত্তর: B
Explanation
ব্যাখ্যা
The Law of Definite Proportions (also called Proust’s Law) states:
"A given chemical compound always contains its component elements in a fixed ratio by mass, and does not depend on its source or method of preparation."
Example: Water (H₂O) always contains hydrogen and oxygen in the mass ratio of 1:8, regardless of its source.