Answer:
The structure of the atom.
Explanation:
The correct answer is - The structure of the atom.
Reason -
An atom is the smallest unit of matter that retains all of the chemical properties of an element.
As you can see in the picture we have +ΔH so that means for this reaction we need to GET heat. so the answer is A. endothermic :))
i hope this is helpful
have a nice day
Answer:
Reacts with salt to from an acid