Nitrogen makes up around 78% of the total atmosphere.
Answer:
Keeps tides on the shore and away from the city
Explanation
Answer:
the unknown substance is a protein
Explanation:
The biuret test is one of the tests for proteins. It can be used to detect peptide linkages. The biuret test is carried out in an alkaline solution. A coordination complex is formed leading to the appearance of a violet color.
Summarily, the biuret method is a colorimetric technique used to test for proteins and peptides. It involves the formation of a purple (violet) complex of Copper salts in alkaline solution.
Hence when the biuret reagent is added to an unknown substance and it turns purple, the unknown substance is a protein
Both carbon and lead belong to Group IV elements, and thus they have the same number of valence electrons.
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each of the other options, the two elements belong to different groups,
and thus they do NOT have the same number of valence electrons.
I hope this helped you, please tell me if I am correct or not <3
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