The answer is D because it sounds like the most ethical answer. The other choices are wrong because the could possibly hurt someone or an animal.
Answer:
Isotopes are basically atoms of an element that have an unequal number of neutrons and protons. Of course the proton number remains the same, but the neutron number either decreases or increases, which leads to an overall change in mass. However, no chemical properties of the atom/element are changed as the electrons are the same number and do not react. In regards to Helium 4, the original number of neutrons in Helium is 2, and protons 2 as well. We see an equal number of neutrons and protons, hence an unchanged mass, and the element is <em>not</em> an isotope.
Any compound with multiple covalent bonds
Stardust atoms are heavier elements, the percentage of star mass in our body is much more impressive. Most hydrogen in our body floats around in the form of water .
