NO₂ is a brown gas while N₂O₄ is colorless. If heating causes a brown color to persist, then this means that heating causes the reaction to shift backwards and produce NO₂. Therefore, the reaction must be exothermic.
D milk turning sour
the other options are physical changes
Non of these bc it makes the most likely
Answer:
c. Cr
Explanation:
The compound is containing 
ion.
If acid reacts with it, CO_2 evolves.
therefore, Cr would form a precipitate when added to an aqueous solution of this compound. Cr2CO3 is the precipitate.
The correct answer will be:
<span>carbon-14 and hydrogen-3 would most likely decay because their neutrons and protons are not equal.
Due to atoms tend to decay when it has excess of either protons or neutrons
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