yes,chemistry needed to study health.
i believe that he is just expressing his gratitude and thanks for being there during your relationship.
It means that he simply does not feel the chemistry needed to keep an intimate/sexual/non-platonic relationship going.
Chemistry, Biology, Calculus
biology and chemistry
Physics, Chemistry and Mathematics.
chemistry
Drugs are chemical products.
biology and chemistry
chemistry add maths
investigation plan
Generally no need. Stomach contents if needed can be examined at autopsy.