Sorry I’m only answering so I could upload
Answer:
thymine is 19%
Explanation:
Acc to Chargaff's rule, amount of Adenine= amount of Thymine as well as amount of Guanine= amount of Cytosine. Amount left for Thymine and Adenine is 38% now. Since both Adenine and Thymine are, again in equal quantities, so therefore percentage of thymine is 19%.
Mass number is the mass number of that particular Element found in the periodic table and the atomic number is the atomic no. Again found in the periodic table
40g(1mol NH3/17.04g per mol), N2's molar mass=28.02g
3CuO+2NH3=>3Cu+N2+3H2O
(2.3473mol NH3)(1 mol N2/2 mol NH3)(28.02g/1mol)=32.8873g N2
15.5/32.8873=47.1306% yield