The answer is chicken.
Biuret test is used to detect the presence of peptide bonds. Peptide bonds exist in proteins, so when they are present the test comes purple(positive).
Protein is found in big amouts in meat, fish and tofu.
From the options the one with the biggest amount of protein is chicken(around 33g/100g) and will cause the highest positive reaction in the biuret test.
Coconut and potato also have it, but its very little. They are rich in other macronutrients.
Cookies are full of sugar, not protein.
Butter is a source of fat, not protein.
The answer is spin.
Each quantum number that describes the two electrons in a helium atom is identical, except for the one that indicates their spin.
I think the answer is blood urea nitrogen
hope it helps
