Answer:
Law of definite proportions, statement that every chemical compound contains fixed and constant proportions (by mass) of its constituent elements.
Answer:

Explanation:
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In this case, according to the rules for the oxidation states in chemical reactions, it is possible to realize that lone elements have 0 and since magnesium is in group 2A, it forms the cation Mg⁺² as it loses electrons and oxygen is in group 6A so it forms the anion O⁻²; therefore resulting oxidation numbers are:

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Answer:
B. Equal amounts of all gases have the same volume at the same
conditions
Explanation:
Amedo Avogadro found the relationship between volume of a gas and the number of molecules contained in the volume.
The law states that "equal volumes of all gases at the same temperature and pressure contains equal number of molecules or moles".
The law describes the behavior of gases when involve in chemical reactions. It enables one to change over at will in any statement about gases from volumes to molecules and vice versa.
So, the right option is B which implies that equal amounts of all gases have the same volume at the same conditions.
Answer:
BaBr2 (aq) + H2SO4 (aq) → BaSO4 (s) + 2 HBr (aq)
Explanation:
This is a precipitation reaction: BaSO4 is the formed precipitate.