The correct option is D.
The hydrogen atoms that are attached to the nitrogen atom in the ammonia molecule are capable of forming hydrogen bond. The hydrogen bond that exist in the ammonia molecule is the reason why it shows higher boiling point compare to the other hydrides. Hydrogen bond occur in ammonia because ammonia is one of the most electronegative elements.
Your answer is going to be A, because it was shoved harder, it will go faster
Answer: only Br2.
Justification.
In a chemical reaction the element that gains electrons experiments a reduction in its oxidation state, that is why it is said that it is reduced.
So, to know what element is being reduced you need to calculate the oxidation states of the elements involved.
Here I indicate the oxidation states of each element if the reaction putting them inside parenthesis:
Reactants side Products side
K (0) K (1+)
Br (0) Br(1-)
So, K lost one electron, increasing its oxidation statefrom 0 to 1+, meaning that it is being oxidized.
And, each atom of Br gained one electron, reducing its oxidation state from 0 to 1-, meaning it is being reduced.
Therefore, the answer is that Br2 is the substance being reduced.
