Because of its chemical structure.
You need to look at the electronegativity and decide wheter the difference of both of the numbers are significant enough to form a polar bond
You can use the mass of neuron divided by the mass of conversion factor: 1.67*10^(-25)/(1.66054*10^(-24))≈1 amu. So the answer is 1 amu.
Answer:
Molecules make scents. Aromatic ones (That is, containing rings of carbon atoms with delocalised electrons). Some unpleasant smells are due to hydrogen and sulphur groups.
Explanation: