The answer is zero!
let me know if you need help with anything else! :)
All of the above, since:
Part of biology is the study of the human body. But not only that, chemistry is really everything, since everything is made of atoms, even you. Understanding atoms and chemistry helps us to understand physics, biology, and all the other sciences, due to how applicable it is. Chemistry is why we have modern inventions and medicine, even. So, knowing how chemistry plays into our everyday lives and what our bodies consume end up impacting the human body, as studied in biology. This incluses bacteria, viruses, and everything in between. :)
An isotope only differs in the number of neutrons it has. All isotopes of an element <span>have the </span>same<span> atomic number (the number of electrons/protons), therefore, they have the </span>same<span> number of electrons/protons and therefore similiar chemical properties.</span>
What is the concentration?