A. pure samples of the same compound contain the same elements combined in the same proportion by mass
B. pure samples of substances are in the same proportion by mass
C. chemical compounds are pure because they contain the same elements
D. matter can neither be created nor destroyed.
Correct Answer: Option A
A. pure samples of the same compound contain the same elements combined in the same proportion by mass
Explanation
The Law of Definite Proportions states that all pure samples of a particular chemical compound contain similar elements combined in the same proportion by mass.